Chapter 10. Virtual machines
10.1. Creating virtual machines
Use one of these procedures to create a virtual machine:
- Quick Start guided tour
- Quick create from the Catalog
- Pasting a pre-configured YAML file with the virtual machine wizard
- Using the CLI
Do not create virtual machines in openshift-*
namespaces. Instead, create a new namespace or use an existing namespace without the openshift
prefix.
When you create virtual machines from the web console, select a virtual machine template that is configured with a boot source. Virtual machine templates with a boot source are labeled as Available boot source or they display a customized label text. Using templates with an available boot source expedites the process of creating virtual machines.
Templates without a boot source are labeled as Boot source required. You can use these templates if you complete the steps for adding a boot source to the virtual machine.
Due to differences in storage behavior, some virtual machine templates are incompatible with single-node OpenShift. To ensure compatibility, do not set the evictionStrategy
field for any templates or virtual machines that use data volumes or storage profiles.
10.1.1. Using a Quick Start to create a virtual machine
The web console provides Quick Starts with instructional guided tours for creating virtual machines. You can access the Quick Starts catalog by selecting the Help menu in the Administrator perspective to view the Quick Starts catalog. When you click on a Quick Start tile and begin the tour, the system guides you through the process.
Tasks in a Quick Start begin with selecting a Red Hat template. Then, you can add a boot source and import the operating system image. Finally, you can save the custom template and use it to create a virtual machine.
Prerequisites
- Access to the website where you can download the URL link for the operating system image.
Procedure
- In the web console, select Quick Starts from the Help menu.
- Click on a tile in the Quick Starts catalog. For example: Creating a Red Hat Linux Enterprise Linux virtual machine.
-
Follow the instructions in the guided tour and complete the tasks for importing an operating system image and creating a virtual machine. The Virtualization
VirtualMachines page displays the virtual machine.
10.1.2. Quick creating a virtual machine
You can quickly create a virtual machine (VM) by using a template with an available boot source.
Procedure
-
Click Virtualization
Catalog in the side menu. Click Boot source available to filter templates with boot sources.
NoteBy default, the template list will show only Default Templates. Click All Items when filtering to see all available templates for your chosen filters.
- Click a template to view its details.
Click Quick Create VirtualMachine to create a VM from the template.
The virtual machine Details page is displayed with the provisioning status.
Verification
- Click Events to view a stream of events as the VM is provisioned.
- Click Console to verify that the VM booted successfully.
10.1.3. Creating a virtual machine from a customized template
Some templates require additional parameters, for example, a PVC with a boot source. You can customize select parameters of a template to create a virtual machine (VM).
Procedure
In the web console, select a template:
-
Click Virtualization
Catalog in the side menu. - Optional: Filter the templates by project, keyword, operating system, or workload profile.
- Click the template that you want to customize.
-
Click Virtualization
- Click Customize VirtualMachine.
- Specify parameters for your VM, including its Name and Disk source. You can optionally specify a data source to clone.
Verification
- Click Events to view a stream of events as the VM is provisioned.
- Click Console to verify that the VM booted successfully.
Refer to the virtual machine fields section when creating a VM from the web console.
10.1.3.1. Networking fields
Name | Description |
---|---|
Name | Name for the network interface controller. |
Model | Indicates the model of the network interface controller. Supported values are e1000e and virtio. |
Network | List of available network attachment definitions. |
Type | List of available binding methods. Select the binding method suitable for the network interface:
|
MAC Address | MAC address for the network interface controller. If a MAC address is not specified, one is assigned automatically. |
10.1.3.2. Storage fields
Name | Selection | Description |
---|---|---|
Source | Blank (creates PVC) | Create an empty disk. |
Import via URL (creates PVC) | Import content via URL (HTTP or HTTPS endpoint). | |
Use an existing PVC | Use a PVC that is already available in the cluster. | |
Clone existing PVC (creates PVC) | Select an existing PVC available in the cluster and clone it. | |
Import via Registry (creates PVC) | Import content via container registry. | |
Container (ephemeral) | Upload content from a container located in a registry accessible from the cluster. The container disk should be used only for read-only filesystems such as CD-ROMs or temporary virtual machines. | |
Name |
Name of the disk. The name can contain lowercase letters ( | |
Size | Size of the disk in GiB. | |
Type | Type of disk. Example: Disk or CD-ROM | |
Interface | Type of disk device. Supported interfaces are virtIO, SATA, and SCSI. | |
Storage Class | The storage class that is used to create the disk. |
Advanced storage settings
The following advanced storage settings are optional and available for Blank, Import via URL, and Clone existing PVC disks. Before OpenShift Virtualization 4.11, if you do not specify these parameters, the system uses the default values from the kubevirt-storage-class-defaults
config map. In OpenShift Virtualization 4.11 and later, the system uses the default values from the storage profile.
Use storage profiles to ensure consistent advanced storage settings when provisioning storage for OpenShift Virtualization.
To manually specify Volume Mode and Access Mode, you must clear the Apply optimized StorageProfile settings checkbox, which is selected by default.
Name | Mode description | Parameter | Parameter description |
---|---|---|---|
Volume Mode | Defines whether the persistent volume uses a formatted file system or raw block state. Default is Filesystem. | Filesystem | Stores the virtual disk on a file system-based volume. |
Block |
Stores the virtual disk directly on the block volume. Only use | ||
Access Mode | Access mode of the persistent volume. | ReadWriteOnce (RWO) | Volume can be mounted as read-write by a single node. |
ReadWriteMany (RWX) | Volume can be mounted as read-write by many nodes at one time. Note This is required for some features, such as live migration of virtual machines between nodes. | ||
ReadOnlyMany (ROX) | Volume can be mounted as read only by many nodes. |
10.1.3.3. Cloud-init fields
Name | Description |
---|---|
Authorized SSH Keys | The user’s public key that is copied to ~/.ssh/authorized_keys on the virtual machine. |
Custom script | Replaces other options with a field in which you paste a custom cloud-init script. |
To configure storage class defaults, use storage profiles. For more information, see Customizing the storage profile.
10.1.3.4. Pasting in a pre-configured YAML file to create a virtual machine
Create a virtual machine by writing or pasting a YAML configuration file. A valid example
virtual machine configuration is provided by default whenever you open the YAML edit screen.
If your YAML configuration is invalid when you click Create, an error message indicates the parameter in which the error occurs. Only one error is shown at a time.
Navigating away from the YAML screen while editing cancels any changes to the configuration you have made.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Click Create and select With YAML.
Write or paste your virtual machine configuration in the editable window.
-
Alternatively, use the
example
virtual machine provided by default in the YAML screen.
-
Alternatively, use the
- Optional: Click Download to download the YAML configuration file in its present state.
- Click Create to create the virtual machine.
The virtual machine is listed on the VirtualMachines page.
10.1.4. Using the CLI to create a virtual machine
You can create a virtual machine from a virtualMachine
manifest.
Procedure
Edit the
VirtualMachine
manifest for your VM. For example, the following manifest configures a Red Hat Enterprise Linux (RHEL) VM:Example 10.1. Example manifest for a RHEL VM
apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: labels: app: <vm_name> 1 name: <vm_name> spec: dataVolumeTemplates: - apiVersion: cdi.kubevirt.io/v1beta1 kind: DataVolume metadata: name: <vm_name> spec: sourceRef: kind: DataSource name: rhel9 namespace: openshift-virtualization-os-images storage: resources: requests: storage: 30Gi running: false template: metadata: labels: kubevirt.io/domain: <vm_name> spec: domain: cpu: cores: 1 sockets: 2 threads: 1 devices: disks: - disk: bus: virtio name: rootdisk - disk: bus: virtio name: cloudinitdisk interfaces: - masquerade: {} name: default rng: {} features: smm: enabled: true firmware: bootloader: efi: {} resources: requests: memory: 8Gi evictionStrategy: LiveMigrate networks: - name: default pod: {} volumes: - dataVolume: name: <vm_name> name: rootdisk - cloudInitNoCloud: userData: |- #cloud-config user: cloud-user password: '<password>' 2 chpasswd: { expire: False } name: cloudinitdisk
Create a virtual machine by using the manifest file:
$ oc create -f <vm_manifest_file>.yaml
Optional: Start the virtual machine:
$ virtctl start <vm_name>
10.1.5. Virtual machine storage volume types
Storage volume type | Description |
---|---|
ephemeral | A local copy-on-write (COW) image that uses a network volume as a read-only backing store. The backing volume must be a PersistentVolumeClaim. The ephemeral image is created when the virtual machine starts and stores all writes locally. The ephemeral image is discarded when the virtual machine is stopped, restarted, or deleted. The backing volume (PVC) is not mutated in any way. |
persistentVolumeClaim | Attaches an available PV to a virtual machine. Attaching a PV allows for the virtual machine data to persist between sessions. Importing an existing virtual machine disk into a PVC by using CDI and attaching the PVC to a virtual machine instance is the recommended method for importing existing virtual machines into OpenShift Container Platform. There are some requirements for the disk to be used within a PVC. |
dataVolume |
Data volumes build on the
Specify |
cloudInitNoCloud | Attaches a disk that contains the referenced cloud-init NoCloud data source, providing user data and metadata to the virtual machine. A cloud-init installation is required inside the virtual machine disk. |
containerDisk | References an image, such as a virtual machine disk, that is stored in the container image registry. The image is pulled from the registry and attached to the virtual machine as a disk when the virtual machine is launched.
A Only RAW and QCOW2 formats are supported disk types for the container image registry. QCOW2 is recommended for reduced image size. Note
A |
emptyDisk | Creates an additional sparse QCOW2 disk that is tied to the life-cycle of the virtual machine interface. The data survives guest-initiated reboots in the virtual machine but is discarded when the virtual machine stops or is restarted from the web console. The empty disk is used to store application dependencies and data that otherwise exceeds the limited temporary file system of an ephemeral disk. The disk capacity size must also be provided. |
10.1.6. About RunStrategies for virtual machines
A RunStrategy
for virtual machines determines a virtual machine instance’s (VMI) behavior, depending on a series of conditions. The spec.runStrategy
setting exists in the virtual machine configuration process as an alternative to the spec.running
setting. The spec.runStrategy
setting allows greater flexibility for how VMIs are created and managed, in contrast to the spec.running
setting with only true
or false
responses. However, the two settings are mutually exclusive. Only either spec.running
or spec.runStrategy
can be used. An error occurs if both are used.
There are four defined RunStrategies.
Always
-
A VMI is always present when a virtual machine is created. A new VMI is created if the original stops for any reason, which is the same behavior as
spec.running: true
. RerunOnFailure
- A VMI is re-created if the previous instance fails due to an error. The instance is not re-created if the virtual machine stops successfully, such as when it shuts down.
Manual
-
The
start
,stop
, andrestart
virtctl client commands can be used to control the VMI’s state and existence. Halted
-
No VMI is present when a virtual machine is created, which is the same behavior as
spec.running: false
.
Different combinations of the start
, stop
and restart
virtctl commands affect which RunStrategy
is used.
The following table follows a VM’s transition from different states. The first column shows the VM’s initial RunStrategy
. Each additional column shows a virtctl command and the new RunStrategy
after that command is run.
Initial RunStrategy | start | stop | restart |
---|---|---|---|
Always | - | Halted | Always |
RerunOnFailure | - | Halted | RerunOnFailure |
Manual | Manual | Manual | Manual |
Halted | Always | - | - |
In OpenShift Virtualization clusters installed using installer-provisioned infrastructure, when a node fails the MachineHealthCheck and becomes unavailable to the cluster, VMs with a RunStrategy of Always
or RerunOnFailure
are rescheduled on a new node.
apiVersion: kubevirt.io/v1
kind: VirtualMachine
spec:
RunStrategy: Always 1
template:
# ...
- 1
- The VMI’s current
RunStrategy
setting.
10.1.7. Additional resources
The
VirtualMachineSpec
definition in the KubeVirt v0.59.0 API Reference provides broader context for the parameters and hierarchy of the virtual machine specification.NoteThe KubeVirt API Reference is the upstream project reference and might contain parameters that are not supported in OpenShift Virtualization.
- Enable the CPU Manager to use the high-performance workload profile.
-
See Prepare a container disk before adding it to a virtual machine as a
containerDisk
volume. - See Deploying machine health checks for further details on deploying and enabling machine health checks.
- See Installer-provisioned infrastructure overview for further details on installer-provisioned infrastructure.
- Customizing the storage profile
10.2. Editing virtual machines
You can update a virtual machine configuration using either the YAML editor in the web console or the OpenShift CLI on the command line. You can also update a subset of the parameters in the Virtual Machine Details screen.
10.2.1. Editing a virtual machine in the web console
You can edit a virtual machine by using the OpenShift Container Platform web console or the command line interface.
Procedure
-
Navigate to Virtualization
VirtualMachines in the web console. - Select a virtual machine to open the VirtualMachine details page.
- Click any field that has the pencil icon, which indicates that the field is editable. For example, click the current Boot mode setting, such as BIOS or UEFI, to open the Boot mode window and select an option from the list.
- Click Save.
If the virtual machine is running, changes to Boot Order or Flavor will not take effect until you restart the virtual machine.
You can view pending changes by clicking View Pending Changes on the right side of the relevant field. The Pending Changes banner at the top of the page displays a list of all changes that will be applied when the virtual machine restarts.
10.2.2. Editing a virtual machine YAML configuration using the web console
You can edit the YAML configuration of a virtual machine in the web console. Some parameters cannot be modified. If you click Save with an invalid configuration, an error message indicates the parameter that cannot be changed.
Navigating away from the YAML screen while editing cancels any changes to the configuration you have made.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select a virtual machine.
- Click the YAML tab to display the editable configuration.
- Optional: You can click Download to download the YAML file locally in its current state.
- Edit the file and click Save.
A confirmation message shows that the modification has been successful and includes the updated version number for the object.
10.2.3. Editing a virtual machine YAML configuration using the CLI
Use this procedure to edit a virtual machine YAML configuration using the CLI.
Prerequisites
- You configured a virtual machine with a YAML object configuration file.
-
You installed the
oc
CLI.
Procedure
Run the following command to update the virtual machine configuration:
$ oc edit <object_type> <object_ID>
- Open the object configuration.
- Edit the YAML.
If you edit a running virtual machine, you need to do one of the following:
- Restart the virtual machine.
Run the following command for the new configuration to take effect:
$ oc apply <object_type> <object_ID>
10.2.4. Adding a virtual disk to a virtual machine
Use this procedure to add a virtual disk to a virtual machine.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
-
On the Configuration
Disks tab, click Add disk. Specify the Source, Name, Size, Type, Interface, and Storage Class.
- Optional: You can enable preallocation if you use a blank disk source and require maximum write performance when creating data volumes. To do so, select the Enable preallocation checkbox.
-
Optional: You can clear Apply optimized StorageProfile settings to change the Volume Mode and Access Mode for the virtual disk. If you do not specify these parameters, the system uses the default values from the
kubevirt-storage-class-defaults
config map.
- Click Add.
If the virtual machine is running, the new disk is in the pending restart state and will not be attached until you restart the virtual machine.
The Pending Changes banner at the top of the page displays a list of all changes that will be applied when the virtual machine restarts.
To configure storage class defaults, use storage profiles. For more information, see Customizing the storage profile.
10.2.4.1. Storage fields
Name | Selection | Description |
---|---|---|
Source | Blank (creates PVC) | Create an empty disk. |
Import via URL (creates PVC) | Import content via URL (HTTP or HTTPS endpoint). | |
Use an existing PVC | Use a PVC that is already available in the cluster. | |
Clone existing PVC (creates PVC) | Select an existing PVC available in the cluster and clone it. | |
Import via Registry (creates PVC) | Import content via container registry. | |
Container (ephemeral) | Upload content from a container located in a registry accessible from the cluster. The container disk should be used only for read-only filesystems such as CD-ROMs or temporary virtual machines. | |
Name |
Name of the disk. The name can contain lowercase letters ( | |
Size | Size of the disk in GiB. | |
Type | Type of disk. Example: Disk or CD-ROM | |
Interface | Type of disk device. Supported interfaces are virtIO, SATA, and SCSI. | |
Storage Class | The storage class that is used to create the disk. |
Advanced storage settings
The following advanced storage settings are optional and available for Blank, Import via URL, and Clone existing PVC disks. Before OpenShift Virtualization 4.11, if you do not specify these parameters, the system uses the default values from the kubevirt-storage-class-defaults
config map. In OpenShift Virtualization 4.11 and later, the system uses the default values from the storage profile.
Use storage profiles to ensure consistent advanced storage settings when provisioning storage for OpenShift Virtualization.
To manually specify Volume Mode and Access Mode, you must clear the Apply optimized StorageProfile settings checkbox, which is selected by default.
Name | Mode description | Parameter | Parameter description |
---|---|---|---|
Volume Mode | Defines whether the persistent volume uses a formatted file system or raw block state. Default is Filesystem. | Filesystem | Stores the virtual disk on a file system-based volume. |
Block |
Stores the virtual disk directly on the block volume. Only use | ||
Access Mode | Access mode of the persistent volume. | ReadWriteOnce (RWO) | Volume can be mounted as read-write by a single node. |
ReadWriteMany (RWX) | Volume can be mounted as read-write by many nodes at one time. Note This is required for some features, such as live migration of virtual machines between nodes. | ||
ReadOnlyMany (ROX) | Volume can be mounted as read only by many nodes. |
10.2.5. Adding a secret, config map, or service account to a virtual machine
You add a secret, config map, or service account to a virtual machine by using the OpenShift Container Platform web console.
These resources are added to the virtual machine as disks. You then mount the secret, config map, or service account as you would mount any other disk.
If the virtual machine is running, changes do not take effect until you restart the virtual machine. The newly added resources are marked as pending changes at the top of the page.
Prerequisites
- The secret, config map, or service account that you want to add must exist in the same namespace as the target virtual machine.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
-
Click Configuration
Environment. - Click Add Config Map, Secret or Service Account.
- Click Select a resource and select a resource from the list. A six character serial number is automatically generated for the selected resource.
- Optional: Click Reload to revert the environment to its last saved state.
- Click Save.
Verification
-
On the VirtualMachine details page, click Configuration
Disks and verify that the resource is displayed in the list of disks. -
Restart the virtual machine by clicking Actions
Restart.
You can now mount the secret, config map, or service account as you would mount any other disk.
Additional resources for config maps, secrets, and service accounts
10.2.6. Adding a network interface to a virtual machine
Use this procedure to add a network interface to a virtual machine.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
-
On the Configuration
Network interfaces tab, click Add Network Interface. - In the Add Network Interface window, specify the Name, Model, Network, Type, and MAC Address of the network interface.
- Click Add.
If the virtual machine is running, the new network interface is in the pending restart state and changes will not take effect until you restart the virtual machine.
The Pending Changes banner at the top of the page displays a list of all changes that will be applied when the virtual machine restarts.
10.2.6.1. Networking fields
Name | Description |
---|---|
Name | Name for the network interface controller. |
Model | Indicates the model of the network interface controller. Supported values are e1000e and virtio. |
Network | List of available network attachment definitions. |
Type | List of available binding methods. Select the binding method suitable for the network interface:
|
MAC Address | MAC address for the network interface controller. If a MAC address is not specified, one is assigned automatically. |
10.3. Editing boot order
You can update the values for a boot order list by using the web console or the CLI.
With Boot Order in the Virtual Machine Overview page, you can:
- Select a disk or network interface controller (NIC) and add it to the boot order list.
- Edit the order of the disks or NICs in the boot order list.
- Remove a disk or NIC from the boot order list, and return it back to the inventory of bootable sources.
10.3.1. Adding items to a boot order list in the web console
Add items to a boot order list by using the web console.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
- Click the Details tab.
- Click the pencil icon that is located on the right side of Boot Order. If a YAML configuration does not exist, or if this is the first time that you are creating a boot order list, the following message displays: No resource selected. VM will attempt to boot from disks by order of appearance in YAML file.
- Click Add Source and select a bootable disk or network interface controller (NIC) for the virtual machine.
- Add any additional disks or NICs to the boot order list.
- Click Save.
If the virtual machine is running, changes to Boot Order will not take effect until you restart the virtual machine.
You can view pending changes by clicking View Pending Changes on the right side of the Boot Order field. The Pending Changes banner at the top of the page displays a list of all changes that will be applied when the virtual machine restarts.
10.3.2. Editing a boot order list in the web console
Edit the boot order list in the web console.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
- Click the Details tab.
- Click the pencil icon that is located on the right side of Boot Order.
Choose the appropriate method to move the item in the boot order list:
- If you do not use a screen reader, hover over the arrow icon next to the item that you want to move, drag the item up or down, and drop it in a location of your choice.
- If you use a screen reader, press the Up Arrow key or Down Arrow key to move the item in the boot order list. Then, press the Tab key to drop the item in a location of your choice.
- Click Save.
If the virtual machine is running, changes to the boot order list will not take effect until you restart the virtual machine.
You can view pending changes by clicking View Pending Changes on the right side of the Boot Order field. The Pending Changes banner at the top of the page displays a list of all changes that will be applied when the virtual machine restarts.
10.3.3. Editing a boot order list in the YAML configuration file
Edit the boot order list in a YAML configuration file by using the CLI.
Procedure
Open the YAML configuration file for the virtual machine by running the following command:
$ oc edit vm example
Edit the YAML file and modify the values for the boot order associated with a disk or network interface controller (NIC). For example:
disks: - bootOrder: 1 1 disk: bus: virtio name: containerdisk - disk: bus: virtio name: cloudinitdisk - cdrom: bus: virtio name: cd-drive-1 interfaces: - boot Order: 2 2 macAddress: '02:96:c4:00:00' masquerade: {} name: default
- Save the YAML file.
- Click reload the content to apply the updated boot order values from the YAML file to the boot order list in the web console.
10.3.4. Removing items from a boot order list in the web console
Remove items from a boot order list by using the web console.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
- Click the Details tab.
- Click the pencil icon that is located on the right side of Boot Order.
- Click the Remove icon next to the item. The item is removed from the boot order list and saved in the list of available boot sources. If you remove all items from the boot order list, the following message displays: No resource selected. VM will attempt to boot from disks by order of appearance in YAML file.
If the virtual machine is running, changes to Boot Order will not take effect until you restart the virtual machine.
You can view pending changes by clicking View Pending Changes on the right side of the Boot Order field. The Pending Changes banner at the top of the page displays a list of all changes that will be applied when the virtual machine restarts.
10.4. Deleting virtual machines
You can delete a virtual machine from the web console or by using the oc
command line interface.
10.4.1. Deleting a virtual machine using the web console
Deleting a virtual machine permanently removes it from the cluster.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
VirtualMachines from the side menu. Click the Options menu beside a virtual machine and select Delete.
Alternatively, click the virtual machine name to open the VirtualMachine details page and click Actions
Delete. - Optional: Select With grace period or clear Delete disks.
- Click Delete to permanently delete the virtual machine.
10.4.2. Deleting a virtual machine by using the CLI
You can delete a virtual machine by using the oc
command line interface (CLI). The oc
client enables you to perform actions on multiple virtual machines.
Prerequisites
- Identify the name of the virtual machine that you want to delete.
Procedure
Delete the virtual machine by running the following command:
$ oc delete vm <vm_name>
NoteThis command only deletes a VM in the current project. Specify the
-n <project_name>
option if the VM you want to delete is in a different project or namespace.
10.5. Exporting virtual machines
You can export a virtual machine (VM) and its associated disks in order to import a VM into another cluster or to analyze the volume for forensic purposes.
You create a VirtualMachineExport
custom resource (CR) by using the command line interface.
Alternatively, you can use the virtctl vmexport
command to create a VirtualMachineExport
CR and to download exported volumes.
10.5.1. Creating a VirtualMachineExport custom resource
You can create a VirtualMachineExport
custom resource (CR) to export the following objects:
- Virtual machine (VM): Exports the persistent volume claims (PVCs) of a specified VM.
-
VM snapshot: Exports PVCs contained in a
VirtualMachineSnapshot
CR. -
PVC: Exports a PVC. If the PVC is used by another pod, such as the
virt-launcher
pod, the export remains in aPending
state until the PVC is no longer in use.
The VirtualMachineExport
CR creates internal and external links for the exported volumes. Internal links are valid within the cluster. External links can be accessed by using an Ingress
or Route
.
The export server supports the following file formats:
-
raw
: Raw disk image file. -
gzip
: Compressed disk image file. -
dir
: PVC directory and files. -
tar.gz
: Compressed PVC file.
Prerequisites
- The VM must be shut down for a VM export.
Procedure
Create a
VirtualMachineExport
manifest to export a volume from aVirtualMachine
,VirtualMachineSnapshot
, orPersistentVolumeClaim
CR according to the following example and save it asexample-export.yaml
:VirtualMachineExport
exampleapiVersion: export.kubevirt.io/v1alpha1 kind: VirtualMachineExport metadata: name: example-export spec: source: apiGroup: "kubevirt.io" 1 kind: VirtualMachine 2 name: example-vm ttlDuration: 1h 3
Create the
VirtualMachineExport
CR:$ oc create -f example-export.yaml
Get the
VirtualMachineExport
CR:$ oc get vmexport example-export -o yaml
The internal and external links for the exported volumes are displayed in the
status
stanza:Output example
apiVersion: export.kubevirt.io/v1alpha1 kind: VirtualMachineExport metadata: name: example-export namespace: example spec: source: apiGroup: "" kind: PersistentVolumeClaim name: example-pvc tokenSecretRef: example-token status: conditions: - lastProbeTime: null lastTransitionTime: "2022-06-21T14:10:09Z" reason: podReady status: "True" type: Ready - lastProbeTime: null lastTransitionTime: "2022-06-21T14:09:02Z" reason: pvcBound status: "True" type: PVCReady links: external: 1 cert: |- -----BEGIN CERTIFICATE----- ... -----END CERTIFICATE----- volumes: - formats: - format: raw url: https://vmexport-proxy.test.net/api/export.kubevirt.io/v1alpha1/namespaces/example/virtualmachineexports/example-export/volumes/example-disk/disk.img - format: gzip url: https://vmexport-proxy.test.net/api/export.kubevirt.io/v1alpha1/namespaces/example/virtualmachineexports/example-export/volumes/example-disk/disk.img.gz name: example-disk internal: 2 cert: |- -----BEGIN CERTIFICATE----- ... -----END CERTIFICATE----- volumes: - formats: - format: raw url: https://virt-export-example-export.example.svc/volumes/example-disk/disk.img - format: gzip url: https://virt-export-example-export.example.svc/volumes/example-disk/disk.img.gz name: example-disk phase: Ready serviceName: virt-export-example-export
10.5.2. Accessing exported virtual machine manifests
After you export a virtual machine (VM) or snapshot, you can get the VirtualMachine
manifest and related information from the export server.
Prerequisites
You exported a virtual machine or VM snapshot by creating a
VirtualMachineExport
custom resource (CR).NoteVirtualMachineExport
objects that have thespec.source.kind: PersistentVolumeClaim
parameter do not generate virtual machine manifests.
Procedure
To access the manifests, you must first copy the certificates from the source cluster to the target cluster.
- Log in to the source cluster.
Save the certificates to the
cacert.crt
file by running the following command:$ oc get vmexport <export_name> -o jsonpath={.status.links.external.cert} > cacert.crt 1
- 1
- Replace
<export_name>
with themetadata.name
value from theVirtualMachineExport
object.
-
Copy the
cacert.crt
file to the target cluster.
Decode the token in the source cluster and save it to the
token_decode
file by running the following command:$ oc get secret export-token-<export_name> -o jsonpath={.data.token} | base64 --decode > token_decode 1
- 1
- Replace
<export_name>
with themetadata.name
value from theVirtualMachineExport
object.
-
Copy the
token_decode
file to the target cluster. Get the
VirtualMachineExport
custom resource by running the following command:$ oc get vmexport <export_name> -o yaml
Review the
status.links
stanza, which is divided intoexternal
andinternal
sections. Note themanifests.url
fields within each section:Example output
apiVersion: export.kubevirt.io/v1alpha1 kind: VirtualMachineExport metadata: name: example-export spec: source: apiGroup: "kubevirt.io" kind: VirtualMachine name: example-vm tokenSecretRef: example-token status: #... links: external: #... manifests: - type: all url: https://vmexport-proxy.test.net/api/export.kubevirt.io/v1alpha1/namespaces/example/virtualmachineexports/example-export/external/manifests/all 1 - type: auth-header-secret url: https://vmexport-proxy.test.net/api/export.kubevirt.io/v1alpha1/namespaces/example/virtualmachineexports/example-export/external/manifests/secret 2 internal: #... manifests: - type: all url: https://virt-export-export-pvc.default.svc/internal/manifests/all 3 - type: auth-header-secret url: https://virt-export-export-pvc.default.svc/internal/manifests/secret phase: Ready serviceName: virt-export-example-export
- 1
- Contains the
VirtualMachine
manifest,DataVolume
manifest, if present, and aConfigMap
manifest that contains the public certificate for the external URL’s ingress or route. - 2
- Contains a secret containing a header that is compatible with Containerized Data Importer (CDI). The header contains a text version of the export token.
- 3
- Contains the
VirtualMachine
manifest,DataVolume
manifest, if present, and aConfigMap
manifest that contains the certificate for the internal URL’s export server.
- Log in to the target cluster.
Get the
Secret
manifest by running the following command:$ curl --cacert cacert.crt <secret_manifest_url> -H \ 1 "x-kubevirt-export-token:token_decode" -H \ 2 "Accept:application/yaml"
For example:
$ curl --cacert cacert.crt https://vmexport-proxy.test.net/api/export.kubevirt.io/v1alpha1/namespaces/example/virtualmachineexports/example-export/external/manifests/secret -H "x-kubevirt-export-token:token_decode" -H "Accept:application/yaml"
Get the manifests of
type: all
, such as theConfigMap
andVirtualMachine
manifests, by running the following command:$ curl --cacert cacert.crt <all_manifest_url> -H \ 1 "x-kubevirt-export-token:token_decode" -H \ 2 "Accept:application/yaml"
For example:
$ curl --cacert cacert.crt https://vmexport-proxy.test.net/api/export.kubevirt.io/v1alpha1/namespaces/example/virtualmachineexports/example-export/external/manifests/all -H "x-kubevirt-export-token:token_decode" -H "Accept:application/yaml"
Next steps
-
You can now create the
ConfigMap
andVirtualMachine
objects on the target cluster by using the exported manifests.
10.5.3. Additional resources
10.6. Managing virtual machine instances
If you have standalone virtual machine instances (VMIs) that were created independently outside of the OpenShift Virtualization environment, you can manage them by using the web console or by using oc
or virtctl
commands from the command-line interface (CLI).
The virtctl
command provides more virtualization options than the oc
command. For example, you can use virtctl
to pause a VM or expose a port.
10.6.1. About virtual machine instances
A virtual machine instance (VMI) is a representation of a running virtual machine (VM). When a VMI is owned by a VM or by another object, you manage it through its owner in the web console or by using the oc
command-line interface (CLI).
A standalone VMI is created and started independently with a script, through automation, or by using other methods in the CLI. In your environment, you might have standalone VMIs that were developed and started outside of the OpenShift Virtualization environment. You can continue to manage those standalone VMIs by using the CLI. You can also use the web console for specific tasks associated with standalone VMIs:
- List standalone VMIs and their details.
- Edit labels and annotations for a standalone VMI.
- Delete a standalone VMI.
When you delete a VM, the associated VMI is automatically deleted. You delete a standalone VMI directly because it is not owned by VMs or other objects.
Before you uninstall OpenShift Virtualization, list and view the standalone VMIs by using the CLI or the web console. Then, delete any outstanding VMIs.
10.6.2. Listing all virtual machine instances using the CLI
You can list all virtual machine instances (VMIs) in your cluster, including standalone VMIs and those owned by virtual machines, by using the oc
command-line interface (CLI).
Procedure
List all VMIs by running the following command:
$ oc get vmis -A
10.6.3. Listing standalone virtual machine instances using the web console
Using the web console, you can list and view standalone virtual machine instances (VMIs) in your cluster that are not owned by virtual machines (VMs).
VMIs that are owned by VMs or other objects are not displayed in the web console. The web console displays only standalone VMIs. If you want to list all VMIs in your cluster, you must use the CLI.
Procedure
Click Virtualization
VirtualMachines from the side menu. You can identify a standalone VMI by a dark colored badge next to its name.
10.6.4. Editing a standalone virtual machine instance using the web console
You can edit the annotations and labels of a standalone virtual machine instance (VMI) using the web console. Other fields are not editable.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
VirtualMachines from the side menu. - Select a standalone VMI to open the VirtualMachineInstance details page.
- On the Details tab, click the pencil icon beside Annotations or Labels.
- Make the relevant changes and click Save.
10.6.5. Deleting a standalone virtual machine instance using the CLI
You can delete a standalone virtual machine instance (VMI) by using the oc
command-line interface (CLI).
Prerequisites
- Identify the name of the VMI that you want to delete.
Procedure
Delete the VMI by running the following command:
$ oc delete vmi <vmi_name>
10.6.6. Deleting a standalone virtual machine instance using the web console
Delete a standalone virtual machine instance (VMI) from the web console.
Procedure
-
In the OpenShift Container Platform web console, click Virtualization
VirtualMachines from the side menu. -
Click Actions
Delete VirtualMachineInstance. - In the confirmation pop-up window, click Delete to permanently delete the standalone VMI.
10.7. Controlling virtual machine states
You can stop, start, restart, and unpause virtual machines from the web console.
You can use virtctl
to manage virtual machine states and perform other actions from the CLI. For example, you can use virtctl
to force stop a VM or expose a port.
10.7.1. Starting a virtual machine
You can start a virtual machine from the web console.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Find the row that contains the virtual machine that you want to start.
Navigate to the appropriate menu for your use case:
To stay on this page, where you can perform actions on multiple virtual machines:
- Click the Options menu located at the far right end of the row.
To view comprehensive information about the selected virtual machine before you start it:
- Access the VirtualMachine details page by clicking the name of the virtual machine.
- Click Actions.
- Select Restart.
- In the confirmation window, click Start to start the virtual machine.
When you start virtual machine that is provisioned from a URL
source for the first time, the virtual machine has a status of Importing while OpenShift Virtualization imports the container from the URL endpoint. Depending on the size of the image, this process might take several minutes.
10.7.2. Restarting a virtual machine
You can restart a running virtual machine from the web console.
To avoid errors, do not restart a virtual machine while it has a status of Importing.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Find the row that contains the virtual machine that you want to restart.
Navigate to the appropriate menu for your use case:
To stay on this page, where you can perform actions on multiple virtual machines:
- Click the Options menu located at the far right end of the row.
To view comprehensive information about the selected virtual machine before you restart it:
- Access the VirtualMachine details page by clicking the name of the virtual machine.
-
Click Actions
Restart.
- In the confirmation window, click Restart to restart the virtual machine.
10.7.3. Stopping a virtual machine
You can stop a virtual machine from the web console.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Find the row that contains the virtual machine that you want to stop.
Navigate to the appropriate menu for your use case:
To stay on this page, where you can perform actions on multiple virtual machines:
- Click the Options menu located at the far right end of the row.
To view comprehensive information about the selected virtual machine before you stop it:
- Access the VirtualMachine details page by clicking the name of the virtual machine.
-
Click Actions
Stop.
- In the confirmation window, click Stop to stop the virtual machine.
10.7.4. Unpausing a virtual machine
You can unpause a paused virtual machine from the web console.
Prerequisites
At least one of your virtual machines must have a status of Paused.
NoteYou can pause virtual machines by using the
virtctl
client.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Find the row that contains the virtual machine that you want to unpause.
Navigate to the appropriate menu for your use case:
To stay on this page, where you can perform actions on multiple virtual machines:
- In the Status column, click Paused.
To view comprehensive information about the selected virtual machine before you unpause it:
- Access the VirtualMachine details page by clicking the name of the virtual machine.
- Click the pencil icon that is located on the right side of Status.
- In the confirmation window, click Unpause to unpause the virtual machine.
10.8. Accessing virtual machine consoles
OpenShift Virtualization provides different virtual machine consoles that you can use to accomplish different product tasks. You can access these consoles through the OpenShift Container Platform web console and by using CLI commands.
Running concurrent VNC connections to a single virtual machine is not currently supported.
10.8.1. Accessing virtual machine consoles in the OpenShift Container Platform web console
You can connect to virtual machines by using the serial console or the VNC console in the OpenShift Container Platform web console.
You can connect to Windows virtual machines by using the desktop viewer console, which uses RDP (remote desktop protocol), in the OpenShift Container Platform web console.
10.8.1.1. Connecting to the serial console
Connect to the serial console of a running virtual machine from the Console tab on the VirtualMachine details page of the web console.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
- Click the Console tab. The VNC console opens by default.
- Click Disconnect to ensure that only one console session is open at a time. Otherwise, the VNC console session remains active in the background.
- Click the VNC Console drop-down list and select Serial Console.
- Click Disconnect to end the console session.
- Optional: Open the serial console in a separate window by clicking Open Console in New Window.
10.8.1.2. Connecting to the VNC console
Connect to the VNC console of a running virtual machine from the Console tab on the VirtualMachine details page of the web console.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
- Click the Console tab. The VNC console opens by default.
- Optional: Open the VNC console in a separate window by clicking Open Console in New Window.
- Optional: Send key combinations to the virtual machine by clicking Send Key.
- Click outside the console window and then click Disconnect to end the session.
10.8.1.3. Connecting to a Windows virtual machine with RDP
The Desktop viewer console, which utilizes the Remote Desktop Protocol (RDP), provides a better console experience for connecting to Windows virtual machines.
To connect to a Windows virtual machine with RDP, download the console.rdp
file for the virtual machine from the Console tab on the VirtualMachine details page of the web console and supply it to your preferred RDP client.
Prerequisites
-
A running Windows virtual machine with the QEMU guest agent installed. The
qemu-guest-agent
is included in the VirtIO drivers. - An RDP client installed on a machine on the same network as the Windows virtual machine.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
VirtualMachines from the side menu. - Click a Windows virtual machine to open the VirtualMachine details page.
- Click the Console tab.
- From the list of consoles, select Desktop viewer.
-
Click Launch Remote Desktop to download the
console.rdp
file. -
Reference the
console.rdp
file in your preferred RDP client to connect to the Windows virtual machine.
10.8.1.4. Switching between virtual machine displays
If your Windows virtual machine (VM) has a vGPU attached, you can switch between the default display and the vGPU display by using the web console.
Prerequisites
-
The mediated device is configured in the
HyperConverged
custom resource and assigned to the VM. - The VM is running.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
VirtualMachines - Select a Windows virtual machine to open the Overview screen.
- Click the Console tab.
- From the list of consoles, select VNC console.
Choose the appropriate key combination from the Send Key list:
-
To access the default VM display, select
Ctl + Alt+ 1
. -
To access the vGPU display, select
Ctl + Alt + 2
.
-
To access the default VM display, select
Additional resources
10.8.1.5. Copying the SSH command using the web console
Copy the command to connect to a virtual machine (VM) terminal via SSH.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
VirtualMachines from the side menu. - Click the Options menu for your virtual machine and select Copy SSH command.
- Paste it in the terminal to access the VM.
10.8.2. Accessing virtual machine consoles by using CLI commands
10.8.2.1. Accessing a virtual machine via SSH by using virtctl
You can use the virtctl ssh
command to forward SSH traffic to a virtual machine (VM) by using your local SSH client. If you have previously configured SSH key authentication with the VM, skip to step 2 of the procedure because step 1 is not required.
Heavy SSH traffic on the control plane can slow down the API server. If you regularly need a large number of connections, use a dedicated Kubernetes Service
object to access the virtual machine.
Prerequisites
-
You have installed the OpenShift CLI (
oc
). -
You have installed the
virtctl
client. - The virtual machine you want to access is running.
- You are in the same project as the VM.
Procedure
Configure SSH key authentication:
Use the
ssh-keygen
command to generate an SSH public key pair:$ ssh-keygen -f <key_file> 1
- 1
- Specify the file in which to store the keys.
Create an SSH authentication secret which contains the SSH public key to access the VM:
$ oc create secret generic my-pub-key --from-file=key1=<key_file>.pub
Add a reference to the secret in the
VirtualMachine
manifest. For example:apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: name: testvm spec: running: true template: spec: accessCredentials: - sshPublicKey: source: secret: secretName: my-pub-key 1 propagationMethod: configDrive: {} 2 # ...
- Restart the VM to apply your changes.
Connect to the VM via SSH:
Run the following command to access the VM via SSH:
$ virtctl ssh -i <key_file> <vm_username>@<vm_name>
Optional: To securely transfer files to or from the VM, use the following commands:
Copy a file from your machine to the VM
$ virtctl scp -i <key_file> <filename> <vm_username>@<vm_name>:
Copy a file from the VM to your machine
$ virtctl scp -i <key_file> <vm_username@<vm_name>:<filename> .
Additional resources
10.8.2.2. Using OpenSSH and virtctl port-forward
You can use your local OpenSSH client and the virtctl port-forward
command to connect to a running virtual machine (VM). You can use this method with Ansible to automate the configuration of VMs.
This method is recommended for low-traffic applications because port-forwarding traffic is sent over the control plane. This method is not recommended for high-traffic applications such as Rsync or Remote Desktop Protocol because it places a heavy burden on the API server.
Prerequisites
-
You have installed the
virtctl
client. - The virtual machine you want to access is running.
-
The environment where you installed the
virtctl
tool has the cluster permissions required to access the VM. For example, you ranoc login
or you set theKUBECONFIG
environment variable.
Procedure
Add the following text to the
~/.ssh/config
file on your client machine:Host vm/* ProxyCommand virtctl port-forward --stdio=true %h %p
Connect to the VM by running the following command:
$ ssh <user>@vm/<vm_name>.<namespace>
10.8.2.3. Accessing the serial console of a virtual machine instance
The virtctl console
command opens a serial console to the specified virtual machine instance.
Prerequisites
-
The
virt-viewer
package must be installed. - The virtual machine instance you want to access must be running.
Procedure
Connect to the serial console with
virtctl
:$ virtctl console <VMI>
10.8.2.4. Accessing the graphical console of a virtual machine instances with VNC
The virtctl
client utility can use the remote-viewer
function to open a graphical console to a running virtual machine instance. This capability is included in the virt-viewer
package.
Prerequisites
-
The
virt-viewer
package must be installed. - The virtual machine instance you want to access must be running.
If you use virtctl
via SSH on a remote machine, you must forward the X session to your machine.
Procedure
Connect to the graphical interface with the
virtctl
utility:$ virtctl vnc <VMI>
If the command failed, try using the
-v
flag to collect troubleshooting information:$ virtctl vnc <VMI> -v 4
10.8.2.5. Connecting to a Windows virtual machine with an RDP console
Create a Kubernetes Service
object to connect to a Windows virtual machine (VM) by using your local Remote Desktop Protocol (RDP) client.
Prerequisites
-
A running Windows virtual machine with the QEMU guest agent installed. The
qemu-guest-agent
object is included in the VirtIO drivers. - An RDP client installed on your local machine.
Procedure
Edit the
VirtualMachine
manifest to add the label for service creation:apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: name: vm-ephemeral namespace: example-namespace spec: running: false template: metadata: labels: special: key 1 # ...
- 1
- Add the label
special: key
in thespec.template.metadata.labels
section.
NoteLabels on a virtual machine are passed through to the pod. The
special: key
label must match the label in thespec.selector
attribute of theService
manifest.-
Save the
VirtualMachine
manifest file to apply your changes. Create a
Service
manifest to expose the VM:apiVersion: v1 kind: Service metadata: name: rdpservice 1 namespace: example-namespace 2 spec: ports: - targetPort: 3389 3 protocol: TCP selector: special: key 4 type: NodePort 5 # ...
- 1
- The name of the
Service
object. - 2
- The namespace where the
Service
object resides. This must match themetadata.namespace
field of theVirtualMachine
manifest. - 3
- The VM port to be exposed by the service. It must reference an open port if a port list is defined in the VM manifest.
- 4
- The reference to the label that you added in the
spec.template.metadata.labels
stanza of theVirtualMachine
manifest. - 5
- The type of service.
-
Save the
Service
manifest file. Create the service by running the following command:
$ oc create -f <service_name>.yaml
- Start the VM. If the VM is already running, restart it.
Query the
Service
object to verify that it is available:$ oc get service -n example-namespace
Example output for
NodePort
serviceNAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE rdpservice NodePort 172.30.232.73 <none> 3389:30000/TCP 5m
Run the following command to obtain the IP address for the node:
$ oc get node <node_name> -o wide
Example output
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP node01 Ready worker 6d22h v1.24.0 192.168.55.101 <none>
- Specify the node IP address and the assigned port in your preferred RDP client.
- Enter the user name and password to connect to the Windows virtual machine.
10.9. Automating Windows installation with sysprep
You can use Microsoft DVD images and sysprep
to automate the installation, setup, and software provisioning of Windows virtual machines.
10.9.1. Using a Windows DVD to create a VM disk image
Microsoft does not provide disk images for download, but you can create a disk image using a Windows DVD. This disk image can then be used to create virtual machines.
Procedure
-
In the OpenShift Virtualization web console, click Storage
PersistentVolumeClaims Create PersistentVolumeClaim With Data upload form. - Select the intended project.
- Set the Persistent Volume Claim Name.
- Upload the VM disk image from the Windows DVD. The image is now available as a boot source to create a new Windows VM.
10.9.2. Using a disk image to install Windows
You can use a disk image to install Windows on your virtual machine.
Prerequisites
- You must create a disk image using a Windows DVD.
-
You must create an
autounattend.xml
answer file. See the Microsoft documentation for details.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
Catalog from the side menu. - Select a Windows template and click Customize VirtualMachine.
- Select Upload (Upload a new file to a PVC) from the Disk source list and browse to the DVD image.
- Click Review and create VirtualMachine.
- Clear Clone available operating system source to this Virtual Machine.
- Clear Start this VirtualMachine after creation.
- On the Sysprep section of the Scripts tab, click Edit.
-
Browse to the
autounattend.xml
answer file and click Save. - Click Create VirtualMachine.
-
On the YAML tab, replace
running:false
withrunStrategy: RerunOnFailure
and click Save.
The VM will start with the sysprep
disk containing the autounattend.xml
answer file.
10.9.3. Generalizing a Windows VM using sysprep
Generalizing an image allows that image to remove all system-specific configuration data when the image is deployed on a virtual machine (VM).
Before generalizing the VM, you must ensure the sysprep
tool cannot detect an answer file after the unattended Windows installation.
Prerequisites
- A running Windows virtual machine with the QEMU guest agent installed.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
VirtualMachines. - Select a Windows VM to open the VirtualMachine details page.
-
Click Configuration
Disks. -
Click the Options menu
beside the
sysprep
disk and select Detach. - Click Detach.
-
Rename
C:\Windows\Panther\unattend.xml
to avoid detection by thesysprep
tool. Start the
sysprep
program by running the following command:%WINDIR%\System32\Sysprep\sysprep.exe /generalize /shutdown /oobe /mode:vm
-
After the
sysprep
tool completes, the Windows VM shuts down. The disk image of the VM is now available to use as an installation image for Windows VMs.
You can now specialize the VM.
10.9.4. Specializing a Windows virtual machine
Specializing a virtual machine (VM) configures the computer-specific information from a generalized Windows image onto the VM.
Prerequisites
- You must have a generalized Windows disk image.
-
You must create an
unattend.xml
answer file. See the Microsoft documentation for details.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
Catalog. - Select a Windows template and click Customize VirtualMachine.
- Select PVC (clone PVC) from the Disk source list.
- Specify the Persistent Volume Claim project and Persistent Volume Claim name of the generalized Windows image.
- Click Review and create VirtualMachine.
- Click the Scripts tab.
-
In the Sysprep section, click Edit, browse to the
unattend.xml
answer file, and click Save. - Click Create VirtualMachine.
During the initial boot, Windows uses the unattend.xml
answer file to specialize the VM. The VM is now ready to use.
10.9.5. Additional resources
10.10. Triggering virtual machine failover by resolving a failed node
If a node fails and machine health checks are not deployed on your cluster, virtual machines (VMs) with RunStrategy: Always
configured are not automatically relocated to healthy nodes. To trigger VM failover, you must manually delete the Node
object.
If you installed your cluster by using installer-provisioned infrastructure and you properly configured machine health checks:
- Failed nodes are automatically recycled.
-
Virtual machines with
RunStrategy
set toAlways
orRerunOnFailure
are automatically scheduled on healthy nodes.
10.10.1. Prerequisites
-
A node where a virtual machine was running has the
NotReady
condition. -
The virtual machine that was running on the failed node has
RunStrategy
set toAlways
. -
You have installed the OpenShift CLI (
oc
).
10.10.2. Deleting nodes from a bare metal cluster
When you delete a node using the CLI, the node object is deleted in Kubernetes, but the pods that exist on the node are not deleted. Any bare pods not backed by a replication controller become inaccessible to OpenShift Container Platform. Pods backed by replication controllers are rescheduled to other available nodes. You must delete local manifest pods.
Procedure
Delete a node from an OpenShift Container Platform cluster running on bare metal by completing the following steps:
Mark the node as unschedulable:
$ oc adm cordon <node_name>
Drain all pods on the node:
$ oc adm drain <node_name> --force=true
This step might fail if the node is offline or unresponsive. Even if the node does not respond, it might still be running a workload that writes to shared storage. To avoid data corruption, power down the physical hardware before you proceed.
Delete the node from the cluster:
$ oc delete node <node_name>
Although the node object is now deleted from the cluster, it can still rejoin the cluster after reboot or if the kubelet service is restarted. To permanently delete the node and all its data, you must decommission the node.
- If you powered down the physical hardware, turn it back on so that the node can rejoin the cluster.
10.10.3. Verifying virtual machine failover
After all resources are terminated on the unhealthy node, a new virtual machine instance (VMI) is automatically created on a healthy node for each relocated VM. To confirm that the VMI was created, view all VMIs by using the oc
CLI.
10.10.3.1. Listing all virtual machine instances using the CLI
You can list all virtual machine instances (VMIs) in your cluster, including standalone VMIs and those owned by virtual machines, by using the oc
command-line interface (CLI).
Procedure
List all VMIs by running the following command:
$ oc get vmis -A
10.11. Installing the QEMU guest agent and VirtIO drivers
The QEMU guest agent is a daemon that runs on the virtual machine and passes information to the host about the virtual machine, users, file systems, and secondary networks.
10.11.1. Installing the QEMU guest agent
10.11.1.1. Installing QEMU guest agent on a Linux virtual machine
The qemu-guest-agent
is widely available and available by default in Red Hat Enterprise Linux (RHEL) virtual machines (VMs). Install the agent and start the service.
To create snapshots of an online (Running state) VM with the highest integrity, install the QEMU guest agent.
The QEMU guest agent takes a consistent snapshot by attempting to quiesce the VM’s file system as much as possible, depending on the system workload. This ensures that in-flight I/O is written to the disk before the snapshot is taken. If the guest agent is not present, quiescing is not possible and a best-effort snapshot is taken. The conditions under which the snapshot was taken are reflected in the snapshot indications that are displayed in the web console or CLI.
Procedure
- Access the virtual machine command line through one of the consoles or by SSH.
Install the QEMU guest agent on the virtual machine:
$ yum install -y qemu-guest-agent
Ensure the service is persistent and start it:
$ systemctl enable --now qemu-guest-agent
Verification
Run the following command to verify that
AgentConnected
is listed in the VM spec:$ oc get vm <vm_name>
10.11.1.2. Installing QEMU guest agent on a Windows virtual machine
For Windows virtual machines, the QEMU guest agent is included in the VirtIO drivers. Install the drivers on an existing or a new Windows installation.
To create snapshots of an online (Running state) VM with the highest integrity, install the QEMU guest agent.
The QEMU guest agent takes a consistent snapshot by attempting to quiesce the VM’s file system as much as possible, depending on the system workload. This ensures that in-flight I/O is written to the disk before the snapshot is taken. If the guest agent is not present, quiescing is not possible and a best-effort snapshot is taken. The conditions under which the snapshot was taken are reflected in the snapshot indications that are displayed in the web console or CLI.
Procedure
-
In the Windows Guest Operating System (OS), use the File Explorer to navigate to the
guest-agent
directory in thevirtio-win
CD drive. -
Run the
qemu-ga-x86_64.msi
installer.
Verification
Run the following command to verify that the output contains the
QEMU Guest Agent
:$ net start
10.11.2. Installing VirtIO drivers
10.11.2.1. Supported VirtIO drivers for Microsoft Windows virtual machines
Driver name | Hardware ID | Description |
---|---|---|
viostor |
VEN_1AF4&DEV_1001 | The block driver. Sometimes displays as an SCSI Controller in the Other devices group. |
viorng |
VEN_1AF4&DEV_1005 | The entropy source driver. Sometimes displays as a PCI Device in the Other devices group. |
NetKVM |
VEN_1AF4&DEV_1000 | The network driver. Sometimes displays as an Ethernet Controller in the Other devices group. Available only if a VirtIO NIC is configured. |
10.11.2.2. About VirtIO drivers
VirtIO drivers are paravirtualized device drivers required for Microsoft Windows virtual machines to run in OpenShift Virtualization. The supported drivers are available in the container-native-virtualization/virtio-win
container disk of the Red Hat Ecosystem Catalog.
The container-native-virtualization/virtio-win
container disk must be attached to the virtual machine as a SATA CD drive to enable driver installation. You can install VirtIO drivers during Windows installation on the virtual machine or added to an existing Windows installation.
After the drivers are installed, the container-native-virtualization/virtio-win
container disk can be removed from the virtual machine.
10.11.2.3. Installing VirtIO drivers on an existing Windows virtual machine
Install the VirtIO drivers from the attached SATA CD drive to an existing Windows virtual machine.
This procedure uses a generic approach to adding drivers to Windows. The process might differ slightly between versions of Windows. See the installation documentation for your version of Windows for specific installation steps.
Procedure
- Start the virtual machine and connect to a graphical console.
- Log in to a Windows user session.
Open Device Manager and expand Other devices to list any Unknown device.
-
Open the
Device Properties
to identify the unknown device. Right-click the device and select Properties. - Click the Details tab and select Hardware Ids in the Property list.
- Compare the Value for the Hardware Ids with the supported VirtIO drivers.
-
Open the
- Right-click the device and select Update Driver Software.
- Click Browse my computer for driver software and browse to the attached SATA CD drive, where the VirtIO drivers are located. The drivers are arranged hierarchically according to their driver type, operating system, and CPU architecture.
- Click Next to install the driver.
- Repeat this process for all the necessary VirtIO drivers.
- After the driver installs, click Close to close the window.
- Reboot the virtual machine to complete the driver installation.
10.11.2.4. Installing VirtIO drivers during Windows installation
Install the virtio
drivers during or after Windows installation.
This procedure uses a generic approach to the Windows installation and the installation method might differ between versions of Windows. See the documentation for the version of Windows that you are installing.
Prerequisites
-
A storage device containing the
virtio
drivers must be attached to the VM.
Procedure
-
In the Windows Guest OS, use the
File Explorer
to navigate to thevirtio-win
CD drive. Double-click to run the appropriate installer for your VM:
-
For a 64-bit vCPU, use the
virtio-win-gt-x64
installer. 32-bit vCPUs are no longer supported.
-
For a 64-bit vCPU, use the
- Optional: During the Custom Setup step of the installer, select the device drivers you want to install. The recommended driver set is selected by default.
- After the installation is complete, select Finish.
- Reboot the VM.
Verification
-
Open the system disk on the PC. This is typically
C:
. -
Navigate to Program Files
Virtio-Win.
If the Virtio-Win directory is present and contains a sub-directory for each driver, the installation was successful.
10.11.2.5. Adding VirtIO drivers container disk to a virtual machine
OpenShift Virtualization distributes VirtIO drivers for Microsoft Windows as a container disk, which is available from the Red Hat Ecosystem Catalog. To install these drivers to a Windows virtual machine, attach the container-native-virtualization/virtio-win
container disk to the virtual machine as a SATA CD drive in the virtual machine configuration file.
Prerequisites
-
Download the
container-native-virtualization/virtio-win
container disk from the Red Hat Ecosystem Catalog. This is not mandatory, because the container disk will be downloaded from the Red Hat registry if it not already present in the cluster, but it can reduce installation time.
Procedure
Add the
container-native-virtualization/virtio-win
container disk as acdrom
disk in the Windows virtual machine configuration file. The container disk will be downloaded from the registry if it is not already present in the cluster.spec: domain: devices: disks: - name: virtiocontainerdisk bootOrder: 2 1 cdrom: bus: sata volumes: - containerDisk: image: container-native-virtualization/virtio-win name: virtiocontainerdisk
- 1
- OpenShift Virtualization boots virtual machine disks in the order defined in the
VirtualMachine
configuration file. You can either define other disks for the virtual machine before thecontainer-native-virtualization/virtio-win
container disk or use the optionalbootOrder
parameter to ensure the virtual machine boots from the correct disk. If you specify thebootOrder
for a disk, it must be specified for all disks in the configuration.
The disk is available once the virtual machine has started:
-
If you add the container disk to a running virtual machine, use
oc apply -f <vm.yaml>
in the CLI or reboot the virtual machine for the changes to take effect. -
If the virtual machine is not running, use
virtctl start <vm>
.
-
If you add the container disk to a running virtual machine, use
After the virtual machine has started, the VirtIO drivers can be installed from the attached SATA CD drive.
10.12. Viewing the QEMU guest agent information for virtual machines
When the QEMU guest agent runs on the virtual machine, you can use the web console to view information about the virtual machine, users, file systems, and secondary networks.
If the QEMU guest agent is not installed, the Overview and the Details tabs display information about the operating system that was specified when the virtual machine was created.
10.12.1. Viewing the QEMU guest agent information in the web console
You can use the web console to view information for virtual machines that is passed by the QEMU guest agent to the host.
Prerequisites
- Install the QEMU guest agent on the virtual machine.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select a virtual machine name to open the VirtualMachine details page.
- Click the Details tab to view active users.
-
Click the Configuration
Disks tab to view information about the file systems.
10.13. Using virtual Trusted Platform Module devices
Add a virtual Trusted Platform Module (vTPM) device to a new or existing virtual machine by editing the VirtualMachine
(VM) or VirtualMachineInstance
(VMI) manifest.
10.13.1. About vTPM devices
A virtual Trusted Platform Module (vTPM) device functions like a physical Trusted Platform Module (TPM) hardware chip.
You can use a vTPM device with any operating system, but Windows 11 requires the presence of a TPM chip to install or boot. A vTPM device allows VMs created from a Windows 11 image to function without a physical TPM chip.
If you do not enable vTPM, then the VM does not recognize a TPM device, even if the node has one.
vTPM devices also protect virtual machines by temporarily storing secrets without physical hardware. However, using vTPM for persistent secret storage is not currently supported. vTPM discards stored secrets after a VM shuts down.
10.13.2. Adding a vTPM device to a virtual machine
Adding a virtual Trusted Platform Module (vTPM) device to a virtual machine (VM) allows you to run a VM created from a Windows 11 image without a physical TPM device. A vTPM device also temporarily stores secrets for that VM.
Procedure
Run the following command to update the VM configuration:
$ oc edit vm <vm_name>
Edit the VM
spec
so that it includes thetpm: {}
line. For example:apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: name: example-vm spec: template: spec: domain: devices: tpm: {} 1 # ...
- 1
- Adds the TPM device to the VM.
- To apply your changes, save and exit the editor.
- Optional: If you edited a running virtual machine, you must restart it for the changes to take effect.
10.14. Managing virtual machines with OpenShift Pipelines
Red Hat OpenShift Pipelines is a Kubernetes-native CI/CD framework that allows developers to design and run each step of the CI/CD pipeline in its own container.
The Tekton Tasks Operator (TTO) integrates OpenShift Virtualization with OpenShift Pipelines. TTO includes cluster tasks and example pipelines that allow you to:
- Create and manage virtual machines (VMs), persistent volume claims (PVCs), and data volumes
- Run commands in VMs
-
Manipulate disk images with
libguestfs
tools
Managing virtual machines with Red Hat OpenShift Pipelines is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.
10.14.1. Prerequisites
-
You have access to an OpenShift Container Platform cluster with
cluster-admin
permissions. -
You have installed the OpenShift CLI (
oc
). - You have installed OpenShift Pipelines.
10.14.2. Deploying the Tekton Tasks Operator resources
The Tekton Tasks Operator (TTO) cluster tasks and example pipelines are not deployed by default when you install OpenShift Virtualization. To deploy TTO resources, enable the deployTektonTaskResources
feature gate in the HyperConverged
custom resource (CR).
Procedure
Open the
HyperConverged
CR in your default editor by running the following command:$ oc edit hco -n openshift-cnv kubevirt-hyperconverged
Set the
spec.featureGates.deployTektonTaskResources
field totrue
.apiVersion: hco.kubevirt.io/v1beta1 kind: HyperConverged metadata: name: kubevirt-hyperconverged namespace: kubevirt-hyperconverged spec: tektonPipelinesNamespace: <user_namespace> 1 featureGates: deployTektonTaskResources: true 2 # ...
NoteThe cluster tasks and example pipelines remain available even if you disable the feature gate later.
- Save your changes and exit the editor.
10.14.3. Virtual machine tasks supported by the Tekton Tasks Operator
The following table shows the cluster tasks that are included as part of the Tekton Tasks Operator.
Task | Description |
---|---|
| Create a virtual machine from a template. |
| Copy a virtual machine template. |
| Modify a virtual machine template. |
| Create or delete data volumes or data sources. |
| Run a script or a command in a virtual machine and stop or delete the virtual machine afterward. |
|
Use the |
|
Use the |
| Wait for a specific status of a virtual machine instance and fail or succeed based on the status. |
10.14.4. Example pipelines
The Tekton Tasks Operator includes the following example Pipeline
manifests. You can run the example pipelines by using the web console or CLI.
You might have to run more than one installer pipline if you need multiple versions of Windows. If you run more than one installer pipeline, each one requires unique parameters, such as the autounattend
config map and base image name. For example, if you need Windows 10 and Windows 11 or Windows Server 2022 images, you have to run both the Windows efi installer pipeline and the Windows bios installer pipeline. However, if you need Windows 11 and Windows Server 2022 images, you have to run only the Windows efi installer pipeline.
- Windows EFI installer pipeline
- This pipeline installs Windows 11 or Windows Server 2022 into a new data volume from a Windows installation image (ISO file). A custom answer file is used to run the installation process.
- Windows BIOS installer pipeline
- This pipeline installs Windows 10 into a new data volume from a Windows installation image, also called an ISO file. A custom answer file is used to run the installation process.
- Windows customize pipeline
- This pipeline clones the data volume of a basic Windows 10, 11, or Windows Server 2022 installation, customizes it by installing Microsoft SQL Server Express or Microsoft Visual Studio Code, and then creates a new image and template.
10.14.4.1. Running the example pipelines using the web console
You can run the example pipelines from the Pipelines menu in the web console.
Procedure
-
Click Pipelines
Pipelines in the side menu. - Select a pipeline to open the Pipeline details page.
- From the Actions list, select Start. The Start Pipeline dialog is displayed.
- Keep the default values for the parameters and then click Start to run the pipeline. The Details tab tracks the progress of each task and displays the pipeline status.
10.14.4.2. Running the example pipelines using the CLI
Use a PipelineRun
resource to run the example pipelines. A PipelineRun
object is the running instance of a pipeline. It instantiates a pipeline for execution with specific inputs, outputs, and execution parameters on a cluster. It also creates a TaskRun
object for each task in the pipeline.
Procedure
To run the Windows 10 installer pipeline, create the following
PipelineRun
manifest:apiVersion: tekton.dev/v1beta1 kind: PipelineRun metadata: generateName: windows10-installer-run- labels: pipelinerun: windows10-installer-run spec: params: - name: winImageDownloadURL value: <link_to_windows_10_iso> 1 pipelineRef: name: windows10-installer taskRunSpecs: - pipelineTaskName: copy-template taskServiceAccountName: copy-template-task - pipelineTaskName: modify-vm-template taskServiceAccountName: modify-vm-template-task - pipelineTaskName: create-vm-from-template taskServiceAccountName: create-vm-from-template-task - pipelineTaskName: wait-for-vmi-status taskServiceAccountName: wait-for-vmi-status-task - pipelineTaskName: create-base-dv taskServiceAccountName: modify-data-object-task - pipelineTaskName: cleanup-vm taskServiceAccountName: cleanup-vm-task status: {}
- 1
- Specify the URL for the Windows 10 64-bit ISO file. The product language must be English (United States).
Apply the
PipelineRun
manifest:$ oc apply -f windows10-installer-run.yaml
To run the Windows 10 customize pipeline, create the following
PipelineRun
manifest:apiVersion: tekton.dev/v1beta1 kind: PipelineRun metadata: generateName: windows10-customize-run- labels: pipelinerun: windows10-customize-run spec: params: - name: allowReplaceGoldenTemplate value: true - name: allowReplaceCustomizationTemplate value: true pipelineRef: name: windows10-customize taskRunSpecs: - pipelineTaskName: copy-template-customize taskServiceAccountName: copy-template-task - pipelineTaskName: modify-vm-template-customize taskServiceAccountName: modify-vm-template-task - pipelineTaskName: create-vm-from-template taskServiceAccountName: create-vm-from-template-task - pipelineTaskName: wait-for-vmi-status taskServiceAccountName: wait-for-vmi-status-task - pipelineTaskName: create-base-dv taskServiceAccountName: modify-data-object-task - pipelineTaskName: cleanup-vm taskServiceAccountName: cleanup-vm-task - pipelineTaskName: copy-template-golden taskServiceAccountName: copy-template-task - pipelineTaskName: modify-vm-template-golden taskServiceAccountName: modify-vm-template-task status: {}
Apply the
PipelineRun
manifest:$ oc apply -f windows10-customize-run.yaml
10.14.5. Additional resources
10.15. Advanced virtual machine management
10.15.1. Working with resource quotas for virtual machines
Create and manage resource quotas for virtual machines.
10.15.1.1. Setting resource quota limits for virtual machines
Resource quotas that only use requests automatically work with virtual machines (VMs). If your resource quota uses limits, you must manually set resource limits on VMs. Resource limits must be at least 100 MiB larger than resource requests.
Procedure
Set limits for a VM by editing the
VirtualMachine
manifest. For example:apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: name: with-limits spec: running: false template: spec: domain: # ... resources: requests: memory: 128Mi limits: memory: 256Mi 1
- 1
- This configuration is supported because the
limits.memory
value is at least100Mi
larger than therequests.memory
value.
-
Save the
VirtualMachine
manifest.
10.15.1.2. Additional resources
10.15.2. Specifying nodes for virtual machines
You can place virtual machines (VMs) on specific nodes by using node placement rules.
10.15.2.1. About node placement for virtual machines
To ensure that virtual machines (VMs) run on appropriate nodes, you can configure node placement rules. You might want to do this if:
- You have several VMs. To ensure fault tolerance, you want them to run on different nodes.
- You have two chatty VMs. To avoid redundant inter-node routing, you want the VMs to run on the same node.
- Your VMs require specific hardware features that are not present on all available nodes.
- You have a pod that adds capabilities to a node, and you want to place a VM on that node so that it can use those capabilities.
Virtual machine placement relies on any existing node placement rules for workloads. If workloads are excluded from specific nodes on the component level, virtual machines cannot be placed on those nodes.
You can use the following rule types in the spec
field of a VirtualMachine
manifest:
nodeSelector
- Allows virtual machines to be scheduled on nodes that are labeled with the key-value pair or pairs that you specify in this field. The node must have labels that exactly match all listed pairs.
affinity
Enables you to use more expressive syntax to set rules that match nodes with virtual machines. For example, you can specify that a rule is a preference, rather than a hard requirement, so that virtual machines are still scheduled if the rule is not satisfied. Pod affinity, pod anti-affinity, and node affinity are supported for virtual machine placement. Pod affinity works for virtual machines because the
VirtualMachine
workload type is based on thePod
object.NoteAffinity rules only apply during scheduling. OpenShift Container Platform does not reschedule running workloads if the constraints are no longer met.
tolerations
- Allows virtual machines to be scheduled on nodes that have matching taints. If a taint is applied to a node, that node only accepts virtual machines that tolerate the taint.
10.15.2.2. Node placement examples
The following example YAML file snippets use nodePlacement
, affinity
, and tolerations
fields to customize node placement for virtual machines.
10.15.2.2.1. Example: VM node placement with nodeSelector
In this example, the virtual machine requires a node that has metadata containing both example-key-1 = example-value-1
and example-key-2 = example-value-2
labels.
If there are no nodes that fit this description, the virtual machine is not scheduled.
Example VM manifest
metadata: name: example-vm-node-selector apiVersion: kubevirt.io/v1 kind: VirtualMachine spec: template: spec: nodeSelector: example-key-1: example-value-1 example-key-2: example-value-2 # ...
10.15.2.2.2. Example: VM node placement with pod affinity and pod anti-affinity
In this example, the VM must be scheduled on a node that has a running pod with the label example-key-1 = example-value-1
. If there is no such pod running on any node, the VM is not scheduled.
If possible, the VM is not scheduled on a node that has any pod with the label example-key-2 = example-value-2
. However, if all candidate nodes have a pod with this label, the scheduler ignores this constraint.
Example VM manifest
metadata: name: example-vm-pod-affinity apiVersion: kubevirt.io/v1 kind: VirtualMachine spec: template: spec: affinity: podAffinity: requiredDuringSchedulingIgnoredDuringExecution: 1 - labelSelector: matchExpressions: - key: example-key-1 operator: In values: - example-value-1 topologyKey: kubernetes.io/hostname podAntiAffinity: preferredDuringSchedulingIgnoredDuringExecution: 2 - weight: 100 podAffinityTerm: labelSelector: matchExpressions: - key: example-key-2 operator: In values: - example-value-2 topologyKey: kubernetes.io/hostname # ...
- 1
- If you use the
requiredDuringSchedulingIgnoredDuringExecution
rule type, the VM is not scheduled if the constraint is not met. - 2
- If you use the
preferredDuringSchedulingIgnoredDuringExecution
rule type, the VM is still scheduled if the constraint is not met, as long as all required constraints are met.
10.15.2.2.3. Example: VM node placement with node affinity
In this example, the VM must be scheduled on a node that has the label example.io/example-key = example-value-1
or the label example.io/example-key = example-value-2
. The constraint is met if only one of the labels is present on the node. If neither label is present, the VM is not scheduled.
If possible, the scheduler avoids nodes that have the label example-node-label-key = example-node-label-value
. However, if all candidate nodes have this label, the scheduler ignores this constraint.
Example VM manifest
metadata: name: example-vm-node-affinity apiVersion: kubevirt.io/v1 kind: VirtualMachine spec: template: spec: affinity: nodeAffinity: requiredDuringSchedulingIgnoredDuringExecution: 1 nodeSelectorTerms: - matchExpressions: - key: example.io/example-key operator: In values: - example-value-1 - example-value-2 preferredDuringSchedulingIgnoredDuringExecution: 2 - weight: 1 preference: matchExpressions: - key: example-node-label-key operator: In values: - example-node-label-value # ...
- 1
- If you use the
requiredDuringSchedulingIgnoredDuringExecution
rule type, the VM is not scheduled if the constraint is not met. - 2
- If you use the
preferredDuringSchedulingIgnoredDuringExecution
rule type, the VM is still scheduled if the constraint is not met, as long as all required constraints are met.
10.15.2.2.4. Example: VM node placement with tolerations
In this example, nodes that are reserved for virtual machines are already labeled with the key=virtualization:NoSchedule
taint. Because this virtual machine has matching tolerations
, it can schedule onto the tainted nodes.
A virtual machine that tolerates a taint is not required to schedule onto a node with that taint.
Example VM manifest
metadata: name: example-vm-tolerations apiVersion: kubevirt.io/v1 kind: VirtualMachine spec: tolerations: - key: "key" operator: "Equal" value: "virtualization" effect: "NoSchedule" # ...
10.15.2.3. Additional resources
10.15.3. Configuring certificate rotation
Configure certificate rotation parameters to replace existing certificates.
10.15.3.1. Configuring certificate rotation
You can do this during OpenShift Virtualization installation in the web console or after installation in the HyperConverged
custom resource (CR).
Procedure
Open the
HyperConverged
CR by running the following command:$ oc edit hco -n openshift-cnv kubevirt-hyperconverged
Edit the
spec.certConfig
fields as shown in the following example. To avoid overloading the system, ensure that all values are greater than or equal to 10 minutes. Express all values as strings that comply with the golangParseDuration
format.apiVersion: hco.kubevirt.io/v1beta1 kind: HyperConverged metadata: name: kubevirt-hyperconverged namespace: openshift-cnv spec: certConfig: ca: duration: 48h0m0s renewBefore: 24h0m0s 1 server: duration: 24h0m0s 2 renewBefore: 12h0m0s 3
- Apply the YAML file to your cluster.
10.15.3.2. Troubleshooting certificate rotation parameters
Deleting one or more certConfig
values causes them to revert to the default values, unless the default values conflict with one of the following conditions:
-
The value of
ca.renewBefore
must be less than or equal to the value ofca.duration
. -
The value of
server.duration
must be less than or equal to the value ofca.duration
. -
The value of
server.renewBefore
must be less than or equal to the value ofserver.duration
.
If the default values conflict with these conditions, you will receive an error.
If you remove the server.duration
value in the following example, the default value of 24h0m0s
is greater than the value of ca.duration
, conflicting with the specified conditions.
Example
certConfig: ca: duration: 4h0m0s renewBefore: 1h0m0s server: duration: 4h0m0s renewBefore: 4h0m0s
This results in the following error message:
error: hyperconvergeds.hco.kubevirt.io "kubevirt-hyperconverged" could not be patched: admission webhook "validate-hco.kubevirt.io" denied the request: spec.certConfig: ca.duration is smaller than server.duration
The error message only mentions the first conflict. Review all certConfig values before you proceed.
10.15.4. Configuring the default CPU model
Use the defaultCPUModel
setting in the HyperConverged
custom resource (CR) to define a cluster-wide default CPU model.
The virtual machine (VM) CPU model depends on the availability of CPU models within the VM and the cluster.
If the VM does not have a defined CPU model:
-
The
defaultCPUModel
is automatically set using the CPU model defined at the cluster-wide level.
-
The
If both the VM and the cluster have a defined CPU model:
- The VM’s CPU model takes precedence.
If neither the VM nor the cluster have a defined CPU model:
- The host-model is automatically set using the CPU model defined at the host level.
10.15.4.1. Configuring the default CPU model
Configure the defaultCPUModel
by updating the HyperConverged
custom resource (CR). You can change the defaultCPUModel
while OpenShift Virtualization is running.
The defaultCPUModel
is case sensitive.
Prerequisites
- Install the OpenShift CLI (oc).
Procedure
Open the
HyperConverged
CR by running the following command:$ oc edit hco -n openshift-cnv kubevirt-hyperconverged
Add the
defaultCPUModel
field to the CR and set the value to the name of a CPU model that exists in the cluster:apiVersion: hco.kubevirt.io/v1beta1 kind: HyperConverged metadata: name: kubevirt-hyperconverged namespace: openshift-cnv spec: defaultCPUModel: "EPYC"
- Apply the YAML file to your cluster.
10.15.5. Using UEFI mode for virtual machines
You can boot a virtual machine (VM) in Unified Extensible Firmware Interface (UEFI) mode.
10.15.5.1. About UEFI mode for virtual machines
Unified Extensible Firmware Interface (UEFI), like legacy BIOS, initializes hardware components and operating system image files when a computer starts. UEFI supports more modern features and customization options than BIOS, enabling faster boot times.
It stores all the information about initialization and startup in a file with a .efi
extension, which is stored on a special partition called EFI System Partition (ESP). The ESP also contains the boot loader programs for the operating system that is installed on the computer.
10.15.5.2. Booting virtual machines in UEFI mode
You can configure a virtual machine to boot in UEFI mode by editing the VirtualMachine
manifest.
Prerequisites
-
Install the OpenShift CLI (
oc
).
Procedure
Edit or create a
VirtualMachine
manifest file. Use thespec.firmware.bootloader
stanza to configure UEFI mode:Booting in UEFI mode with secure boot active
apiversion: kubevirt.io/v1 kind: VirtualMachine metadata: labels: special: vm-secureboot name: vm-secureboot spec: template: metadata: labels: special: vm-secureboot spec: domain: devices: disks: - disk: bus: virtio name: containerdisk features: acpi: {} smm: enabled: true 1 firmware: bootloader: efi: secureBoot: true 2 # ...
- 1
- OpenShift Virtualization requires System Management Mode (
SMM
) to be enabled for Secure Boot in UEFI mode to occur. - 2
- OpenShift Virtualization supports a VM with or without Secure Boot when using UEFI mode. If Secure Boot is enabled, then UEFI mode is required. However, UEFI mode can be enabled without using Secure Boot.
Apply the manifest to your cluster by running the following command:
$ oc create -f <file_name>.yaml
10.15.6. Configuring PXE booting for virtual machines
PXE booting, or network booting, is available in OpenShift Virtualization. Network booting allows a computer to boot and load an operating system or other program without requiring a locally attached storage device. For example, you can use it to choose your desired OS image from a PXE server when deploying a new host.
10.15.6.1. Prerequisites
- A Linux bridge must be connected.
- The PXE server must be connected to the same VLAN as the bridge.
10.15.6.2. PXE booting with a specified MAC address
As an administrator, you can boot a client over the network by first creating a NetworkAttachmentDefinition
object for your PXE network. Then, reference the network attachment definition in your virtual machine instance configuration file before you start the virtual machine instance. You can also specify a MAC address in the virtual machine instance configuration file, if required by the PXE server.
Prerequisites
- A Linux bridge must be connected.
- The PXE server must be connected to the same VLAN as the bridge.
Procedure
Configure a PXE network on the cluster:
Create the network attachment definition file for PXE network
pxe-net-conf
:apiVersion: "k8s.cni.cncf.io/v1" kind: NetworkAttachmentDefinition metadata: name: pxe-net-conf spec: config: '{ "cniVersion": "0.3.1", "name": "pxe-net-conf", "plugins": [ { "type": "cnv-bridge", "bridge": "br1", "vlan": 1 1 }, { "type": "cnv-tuning" 2 } ] }'
NoteThe virtual machine instance will be attached to the bridge
br1
through an access port with the requested VLAN.
Create the network attachment definition by using the file you created in the previous step:
$ oc create -f pxe-net-conf.yaml
Edit the virtual machine instance configuration file to include the details of the interface and network.
Specify the network and MAC address, if required by the PXE server. If the MAC address is not specified, a value is assigned automatically.
Ensure that
bootOrder
is set to1
so that the interface boots first. In this example, the interface is connected to a network called<pxe-net>
:interfaces: - masquerade: {} name: default - bridge: {} name: pxe-net macAddress: de:00:00:00:00:de bootOrder: 1
NoteBoot order is global for interfaces and disks.
Assign a boot device number to the disk to ensure proper booting after operating system provisioning.
Set the disk
bootOrder
value to2
:devices: disks: - disk: bus: virtio name: containerdisk bootOrder: 2
Specify that the network is connected to the previously created network attachment definition. In this scenario,
<pxe-net>
is connected to the network attachment definition called<pxe-net-conf>
:networks: - name: default pod: {} - name: pxe-net multus: networkName: pxe-net-conf
Create the virtual machine instance:
$ oc create -f vmi-pxe-boot.yaml
Example output
virtualmachineinstance.kubevirt.io "vmi-pxe-boot" created
Wait for the virtual machine instance to run:
$ oc get vmi vmi-pxe-boot -o yaml | grep -i phase phase: Running
View the virtual machine instance using VNC:
$ virtctl vnc vmi-pxe-boot
- Watch the boot screen to verify that the PXE boot is successful.
Log in to the virtual machine instance:
$ virtctl console vmi-pxe-boot
Verify the interfaces and MAC address on the virtual machine and that the interface connected to the bridge has the specified MAC address. In this case, we used
eth1
for the PXE boot, without an IP address. The other interface,eth0
, got an IP address from OpenShift Container Platform.$ ip addr
Example output
... 3. eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether de:00:00:00:00:de brd ff:ff:ff:ff:ff:ff
10.15.6.3. OpenShift Virtualization networking glossary
OpenShift Virtualization provides advanced networking functionality by using custom resources and plugins.
The following terms are used throughout OpenShift Virtualization documentation:
- Container Network Interface (CNI)
- a Cloud Native Computing Foundation project, focused on container network connectivity. OpenShift Virtualization uses CNI plugins to build upon the basic Kubernetes networking functionality.
- Multus
- a "meta" CNI plugin that allows multiple CNIs to exist so that a pod or virtual machine can use the interfaces it needs.
- Custom resource definition (CRD)
- a Kubernetes API resource that allows you to define custom resources, or an object defined by using the CRD API resource.
- Network attachment definition (NAD)
- a CRD introduced by the Multus project that allows you to attach pods, virtual machines, and virtual machine instances to one or more networks.
- Node network configuration policy (NNCP)
-
a description of the requested network configuration on nodes. You update the node network configuration, including adding and removing interfaces, by applying a
NodeNetworkConfigurationPolicy
manifest to the cluster. - Preboot eXecution Environment (PXE)
- an interface that enables an administrator to boot a client machine from a server over the network. Network booting allows you to remotely load operating systems and other software onto the client.
10.15.7. Using huge pages with virtual machines
You can use huge pages as backing memory for virtual machines in your cluster.
10.15.7.1. Prerequisites
- Nodes must have pre-allocated huge pages configured.
10.15.7.2. What huge pages do
Memory is managed in blocks known as pages. On most systems, a page is 4Ki. 1Mi of memory is equal to 256 pages; 1Gi of memory is 256,000 pages, and so on. CPUs have a built-in memory management unit that manages a list of these pages in hardware. The Translation Lookaside Buffer (TLB) is a small hardware cache of virtual-to-physical page mappings. If the virtual address passed in a hardware instruction can be found in the TLB, the mapping can be determined quickly. If not, a TLB miss occurs, and the system falls back to slower, software-based address translation, resulting in performance issues. Since the size of the TLB is fixed, the only way to reduce the chance of a TLB miss is to increase the page size.
A huge page is a memory page that is larger than 4Ki. On x86_64 architectures, there are two common huge page sizes: 2Mi and 1Gi. Sizes vary on other architectures. To use huge pages, code must be written so that applications are aware of them. Transparent Huge Pages (THP) attempt to automate the management of huge pages without application knowledge, but they have limitations. In particular, they are limited to 2Mi page sizes. THP can lead to performance degradation on nodes with high memory utilization or fragmentation due to defragmenting efforts of THP, which can lock memory pages. For this reason, some applications may be designed to (or recommend) usage of pre-allocated huge pages instead of THP.
In OpenShift Virtualization, virtual machines can be configured to consume pre-allocated huge pages.
10.15.7.3. Configuring huge pages for virtual machines
You can configure virtual machines to use pre-allocated huge pages by including the memory.hugepages.pageSize
and resources.requests.memory
parameters in your virtual machine configuration.
The memory request must be divisible by the page size. For example, you cannot request 500Mi
memory with a page size of 1Gi
.
The memory layouts of the host and the guest OS are unrelated. Huge pages requested in the virtual machine manifest apply to QEMU. Huge pages inside the guest can only be configured based on the amount of available memory of the virtual machine instance.
If you edit a running virtual machine, the virtual machine must be rebooted for the changes to take effect.
Prerequisites
- Nodes must have pre-allocated huge pages configured.
Procedure
In your virtual machine configuration, add the
resources.requests.memory
andmemory.hugepages.pageSize
parameters to thespec.domain
. The following configuration snippet is for a virtual machine that requests a total of4Gi
memory with a page size of1Gi
:kind: VirtualMachine # ... spec: domain: resources: requests: memory: "4Gi" 1 memory: hugepages: pageSize: "1Gi" 2 # ...
Apply the virtual machine configuration:
$ oc apply -f <virtual_machine>.yaml
10.15.8. Enabling dedicated resources for virtual machines
To improve performance, you can dedicate node resources, such as CPU, to a virtual machine.
10.15.8.1. About dedicated resources
When you enable dedicated resources for your virtual machine, your virtual machine’s workload is scheduled on CPUs that will not be used by other processes. By using dedicated resources, you can improve the performance of the virtual machine and the accuracy of latency predictions.
10.15.8.2. Prerequisites
-
The CPU Manager must be configured on the node. Verify that the node has the
cpumanager = true
label before scheduling virtual machine workloads. - The virtual machine must be powered off.
10.15.8.3. Enabling dedicated resources for a virtual machine
You enable dedicated resources for a virtual machine in the Details tab. Virtual machines that were created from a Red Hat template can be configured with dedicated resources.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
-
On the Configuration
Scheduling tab, click the edit icon beside Dedicated Resources. - Select Schedule this workload with dedicated resources (guaranteed policy).
- Click Save.
10.15.9. Scheduling virtual machines
You can schedule a virtual machine (VM) on a node by ensuring that the VM’s CPU model and policy attribute are matched for compatibility with the CPU models and policy attributes supported by the node.
10.15.9.1. Policy attributes
You can schedule a virtual machine (VM) by specifying a policy attribute and a CPU feature that is matched for compatibility when the VM is scheduled on a node. A policy attribute specified for a VM determines how that VM is scheduled on a node.
Policy attribute | Description |
---|---|
force | The VM is forced to be scheduled on a node. This is true even if the host CPU does not support the VM’s CPU. |
require | Default policy that applies to a VM if the VM is not configured with a specific CPU model and feature specification. If a node is not configured to support CPU node discovery with this default policy attribute or any one of the other policy attributes, VMs are not scheduled on that node. Either the host CPU must support the VM’s CPU or the hypervisor must be able to emulate the supported CPU model. |
optional | The VM is added to a node if that VM is supported by the host’s physical machine CPU. |
disable | The VM cannot be scheduled with CPU node discovery. |
forbid | The VM is not scheduled even if the feature is supported by the host CPU and CPU node discovery is enabled. |
10.15.9.2. Setting a policy attribute and CPU feature
You can set a policy attribute and CPU feature for each virtual machine (VM) to ensure that it is scheduled on a node according to policy and feature. The CPU feature that you set is verified to ensure that it is supported by the host CPU or emulated by the hypervisor.
Procedure
Edit the
domain
spec of your VM configuration file. The following example sets the CPU feature and therequire
policy for a virtual machine (VM):apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: name: myvm spec: template: spec: domain: cpu: features: - name: apic 1 policy: require 2
10.15.9.3. Scheduling virtual machines with the supported CPU model
You can configure a CPU model for a virtual machine (VM) to schedule it on a node where its CPU model is supported.
Procedure
Edit the
domain
spec of your virtual machine configuration file. The following example shows a specific CPU model defined for a VM:apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: name: myvm spec: template: spec: domain: cpu: model: Conroe 1
- 1
- CPU model for the VM.
10.15.9.4. Scheduling virtual machines with the host model
When the CPU model for a virtual machine (VM) is set to host-model
, the VM inherits the CPU model of the node where it is scheduled.
Procedure
Edit the
domain
spec of your VM configuration file. The following example showshost-model
being specified for the virtual machine:apiVersion: kubevirt/v1alpha3 kind: VirtualMachine metadata: name: myvm spec: template: spec: domain: cpu: model: host-model 1
- 1
- The VM that inherits the CPU model of the node where it is scheduled.
10.15.10. Configuring PCI passthrough
The Peripheral Component Interconnect (PCI) passthrough feature enables you to access and manage hardware devices from a virtual machine. When PCI passthrough is configured, the PCI devices function as if they were physically attached to the guest operating system.
Cluster administrators can expose and manage host devices that are permitted to be used in the cluster by using the oc
command-line interface (CLI).
10.15.10.1. About preparing a host device for PCI passthrough
To prepare a host device for PCI passthrough by using the CLI, create a MachineConfig
object and add kernel arguments to enable the Input-Output Memory Management Unit (IOMMU). Bind the PCI device to the Virtual Function I/O (VFIO) driver and then expose it in the cluster by editing the permittedHostDevices
field of the HyperConverged
custom resource (CR). The permittedHostDevices
list is empty when you first install the OpenShift Virtualization Operator.
To remove a PCI host device from the cluster by using the CLI, delete the PCI device information from the HyperConverged
CR.
10.15.10.1.1. Adding kernel arguments to enable the IOMMU driver
To enable the IOMMU (Input-Output Memory Management Unit) driver in the kernel, create the MachineConfig
object and add the kernel arguments.
Prerequisites
- Administrative privilege to a working OpenShift Container Platform cluster.
- Intel or AMD CPU hardware.
- Intel Virtualization Technology for Directed I/O extensions or AMD IOMMU in the BIOS (Basic Input/Output System) is enabled.
Procedure
Create a
MachineConfig
object that identifies the kernel argument. The following example shows a kernel argument for an Intel CPU.apiVersion: machineconfiguration.openshift.io/v1 kind: MachineConfig metadata: labels: machineconfiguration.openshift.io/role: worker 1 name: 100-worker-iommu 2 spec: config: ignition: version: 3.2.0 kernelArguments: - intel_iommu=on 3 # ...
Create the new
MachineConfig
object:$ oc create -f 100-worker-kernel-arg-iommu.yaml
Verification
Verify that the new
MachineConfig
object was added.$ oc get MachineConfig
10.15.10.1.2. Binding PCI devices to the VFIO driver
To bind PCI devices to the VFIO (Virtual Function I/O) driver, obtain the values for vendor-ID
and device-ID
from each device and create a list with the values. Add this list to the MachineConfig
object. The MachineConfig
Operator generates the /etc/modprobe.d/vfio.conf
on the nodes with the PCI devices, and binds the PCI devices to the VFIO driver.
Prerequisites
- You added kernel arguments to enable IOMMU for the CPU.
Procedure
Run the
lspci
command to obtain thevendor-ID
and thedevice-ID
for the PCI device.$ lspci -nnv | grep -i nvidia
Example output
02:01.0 3D controller [0302]: NVIDIA Corporation GV100GL [Tesla V100 PCIe 32GB] [10de:1eb8] (rev a1)
Create a Butane config file,
100-worker-vfiopci.bu
, binding the PCI device to the VFIO driver.NoteSee "Creating machine configs with Butane" for information about Butane.
Example
variant: openshift version: 4.13.0 metadata: name: 100-worker-vfiopci labels: machineconfiguration.openshift.io/role: worker 1 storage: files: - path: /etc/modprobe.d/vfio.conf mode: 0644 overwrite: true contents: inline: | options vfio-pci ids=10de:1eb8 2 - path: /etc/modules-load.d/vfio-pci.conf 3 mode: 0644 overwrite: true contents: inline: vfio-pci
- 1
- Applies the new kernel argument only to worker nodes.
- 2
- Specify the previously determined
vendor-ID
value (10de
) and thedevice-ID
value (1eb8
) to bind a single device to the VFIO driver. You can add a list of multiple devices with their vendor and device information. - 3
- The file that loads the vfio-pci kernel module on the worker nodes.
Use Butane to generate a
MachineConfig
object file,100-worker-vfiopci.yaml
, containing the configuration to be delivered to the worker nodes:$ butane 100-worker-vfiopci.bu -o 100-worker-vfiopci.yaml
Apply the
MachineConfig
object to the worker nodes:$ oc apply -f 100-worker-vfiopci.yaml
Verify that the
MachineConfig
object was added.$ oc get MachineConfig
Example output
NAME GENERATEDBYCONTROLLER IGNITIONVERSION AGE 00-master d3da910bfa9f4b599af4ed7f5ac270d55950a3a1 3.2.0 25h 00-worker d3da910bfa9f4b599af4ed7f5ac270d55950a3a1 3.2.0 25h 01-master-container-runtime d3da910bfa9f4b599af4ed7f5ac270d55950a3a1 3.2.0 25h 01-master-kubelet d3da910bfa9f4b599af4ed7f5ac270d55950a3a1 3.2.0 25h 01-worker-container-runtime d3da910bfa9f4b599af4ed7f5ac270d55950a3a1 3.2.0 25h 01-worker-kubelet d3da910bfa9f4b599af4ed7f5ac270d55950a3a1 3.2.0 25h 100-worker-iommu 3.2.0 30s 100-worker-vfiopci-configuration 3.2.0 30s
Verification
Verify that the VFIO driver is loaded.
$ lspci -nnk -d 10de:
The output confirms that the VFIO driver is being used.
Example output
04:00.0 3D controller [0302]: NVIDIA Corporation GP102GL [Tesla P40] [10de:1eb8] (rev a1) Subsystem: NVIDIA Corporation Device [10de:1eb8] Kernel driver in use: vfio-pci Kernel modules: nouveau
10.15.10.1.3. Exposing PCI host devices in the cluster using the CLI
To expose PCI host devices in the cluster, add details about the PCI devices to the spec.permittedHostDevices.pciHostDevices
array of the HyperConverged
custom resource (CR).
Procedure
Edit the
HyperConverged
CR in your default editor by running the following command:$ oc edit hyperconverged kubevirt-hyperconverged -n openshift-cnv
Add the PCI device information to the
spec.permittedHostDevices.pciHostDevices
array. For example:Example configuration file
apiVersion: hco.kubevirt.io/v1 kind: HyperConverged metadata: name: kubevirt-hyperconverged namespace: openshift-cnv spec: permittedHostDevices: 1 pciHostDevices: 2 - pciDeviceSelector: "10DE:1DB6" 3 resourceName: "nvidia.com/GV100GL_Tesla_V100" 4 - pciDeviceSelector: "10DE:1EB8" resourceName: "nvidia.com/TU104GL_Tesla_T4" - pciDeviceSelector: "8086:6F54" resourceName: "intel.com/qat" externalResourceProvider: true 5 # ...
- 1
- The host devices that are permitted to be used in the cluster.
- 2
- The list of PCI devices available on the node.
- 3
- The
vendor-ID
and thedevice-ID
required to identify the PCI device. - 4
- The name of a PCI host device.
- 5
- Optional: Setting this field to
true
indicates that the resource is provided by an external device plugin. OpenShift Virtualization allows the usage of this device in the cluster but leaves the allocation and monitoring to an external device plugin.
NoteThe above example snippet shows two PCI host devices that are named
nvidia.com/GV100GL_Tesla_V100
andnvidia.com/TU104GL_Tesla_T4
added to the list of permitted host devices in theHyperConverged
CR. These devices have been tested and verified to work with OpenShift Virtualization.- Save your changes and exit the editor.
Verification
Verify that the PCI host devices were added to the node by running the following command. The example output shows that there is one device each associated with the
nvidia.com/GV100GL_Tesla_V100
,nvidia.com/TU104GL_Tesla_T4
, andintel.com/qat
resource names.$ oc describe node <node_name>
Example output
Capacity: cpu: 64 devices.kubevirt.io/kvm: 110 devices.kubevirt.io/tun: 110 devices.kubevirt.io/vhost-net: 110 ephemeral-storage: 915128Mi hugepages-1Gi: 0 hugepages-2Mi: 0 memory: 131395264Ki nvidia.com/GV100GL_Tesla_V100 1 nvidia.com/TU104GL_Tesla_T4 1 intel.com/qat: 1 pods: 250 Allocatable: cpu: 63500m devices.kubevirt.io/kvm: 110 devices.kubevirt.io/tun: 110 devices.kubevirt.io/vhost-net: 110 ephemeral-storage: 863623130526 hugepages-1Gi: 0 hugepages-2Mi: 0 memory: 130244288Ki nvidia.com/GV100GL_Tesla_V100 1 nvidia.com/TU104GL_Tesla_T4 1 intel.com/qat: 1 pods: 250
10.15.10.1.4. Removing PCI host devices from the cluster using the CLI
To remove a PCI host device from the cluster, delete the information for that device from the HyperConverged
custom resource (CR).
Procedure
Edit the
HyperConverged
CR in your default editor by running the following command:$ oc edit hyperconverged kubevirt-hyperconverged -n openshift-cnv
Remove the PCI device information from the
spec.permittedHostDevices.pciHostDevices
array by deleting thepciDeviceSelector
,resourceName
andexternalResourceProvider
(if applicable) fields for the appropriate device. In this example, theintel.com/qat
resource has been deleted.Example configuration file
apiVersion: hco.kubevirt.io/v1 kind: HyperConverged metadata: name: kubevirt-hyperconverged namespace: openshift-cnv spec: permittedHostDevices: pciHostDevices: - pciDeviceSelector: "10DE:1DB6" resourceName: "nvidia.com/GV100GL_Tesla_V100" - pciDeviceSelector: "10DE:1EB8" resourceName: "nvidia.com/TU104GL_Tesla_T4" # ...
- Save your changes and exit the editor.
Verification
Verify that the PCI host device was removed from the node by running the following command. The example output shows that there are zero devices associated with the
intel.com/qat
resource name.$ oc describe node <node_name>
Example output
Capacity: cpu: 64 devices.kubevirt.io/kvm: 110 devices.kubevirt.io/tun: 110 devices.kubevirt.io/vhost-net: 110 ephemeral-storage: 915128Mi hugepages-1Gi: 0 hugepages-2Mi: 0 memory: 131395264Ki nvidia.com/GV100GL_Tesla_V100 1 nvidia.com/TU104GL_Tesla_T4 1 intel.com/qat: 0 pods: 250 Allocatable: cpu: 63500m devices.kubevirt.io/kvm: 110 devices.kubevirt.io/tun: 110 devices.kubevirt.io/vhost-net: 110 ephemeral-storage: 863623130526 hugepages-1Gi: 0 hugepages-2Mi: 0 memory: 130244288Ki nvidia.com/GV100GL_Tesla_V100 1 nvidia.com/TU104GL_Tesla_T4 1 intel.com/qat: 0 pods: 250
10.15.10.2. Configuring virtual machines for PCI passthrough
After the PCI devices have been added to the cluster, you can assign them to virtual machines. The PCI devices are now available as if they are physically connected to the virtual machines.
10.15.10.2.1. Assigning a PCI device to a virtual machine
When a PCI device is available in a cluster, you can assign it to a virtual machine and enable PCI passthrough.
Procedure
Assign the PCI device to a virtual machine as a host device.
Example
apiVersion: kubevirt.io/v1 kind: VirtualMachine spec: domain: devices: hostDevices: - deviceName: nvidia.com/TU104GL_Tesla_T4 1 name: hostdevices1
- 1
- The name of the PCI device that is permitted on the cluster as a host device. The virtual machine can access this host device.
Verification
Use the following command to verify that the host device is available from the virtual machine.
$ lspci -nnk | grep NVIDIA
Example output
$ 02:01.0 3D controller [0302]: NVIDIA Corporation GV100GL [Tesla V100 PCIe 32GB] [10de:1eb8] (rev a1)
10.15.10.3. Additional resources
10.15.11. Configuring vGPU passthrough
Your virtual machines can access a virtual GPU (vGPU) hardware. Assigning a vGPU to your virtual machine allows you do the following:
- Access a fraction of the underlying hardware’s GPU to achieve high performance benefits in your virtual machine.
- Streamline resource-intensive I/O operations.
vGPU passthrough can only be assigned to devices that are connected to clusters running in a bare metal environment.
10.15.11.1. Assigning vGPU passthrough devices to a virtual machine
Use the OpenShift Container Platform web console to assign vGPU passthrough devices to your virtual machine.
Prerequisites
- The virtual machine must be stopped.
Procedure
-
In the OpenShift Container Platform web console, click Virtualization
VirtualMachines from the side menu. - Select the virtual machine to which you want to assign the device.
On the Details tab, click GPU devices.
If you add a vGPU device as a host device, you cannot access the device with the VNC console.
- Click Add GPU device, enter the Name and select the device from the Device name list.
- Click Save.
-
Click the YAML tab to verify that the new devices have been added to your cluster configuration in the
hostDevices
section.
You can add hardware devices to virtual machines created from customized templates or a YAML file. You cannot add devices to pre-supplied boot source templates for specific operating systems, such as Windows 10 or RHEL 7.
To display resources that are connected to your cluster, click Compute
10.15.11.2. Additional resources
10.15.12. Configuring mediated devices
OpenShift Virtualization automatically creates mediated devices, such as virtual GPUs (vGPUs), if you provide a list of devices in the HyperConverged
custom resource (CR).
Declarative configuration of mediated devices is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.
10.15.12.1. About using the NVIDIA GPU Operator
The NVIDIA GPU Operator manages NVIDIA GPU resources in a OpenShift Container Platform cluster and automates tasks related to bootstrapping GPU nodes. Because the GPU is a special resource in the cluster, you must install some components before you can deploy application workloads to the GPU. These components include the NVIDIA drivers that enable the compute unified device architecture (CUDA), Kubernetes device plugin, container runtime, and other features such as automatic node labeling, monitoring, and more.
The NVIDIA GPU Operator is supported only by NVIDIA. For more information about obtaining support from NVIDIA, see Obtaining Support from NVIDIA.
There are two ways to enable GPUs with OpenShift Container Platform OpenShift Virtualization: the OpenShift Container Platform-native way described here and by using the NVIDIA GPU Operator.
The NVIDIA GPU Operator is a Kubernetes Operator that uses OpenShift Container Platform OpenShift Virtualization to provision GPUs for virtualized workloads running on OpenShift Container Platform. With the Operator, you can easily provision and manage GPU-enabled virtual machines to run complex artificial intelligence/machine learning (AI/ML) workloads on the same platform as their other workloads. The Operator also provides an easy way to scale the GPU capacity of their infrastructure, enabling rapid growth of GPU-based workloads.
For more information about using the NVIDIA GPU Operator to provision worker nodes for running GPU-accelerated VMs, see NVIDIA GPU Operator with OpenShift Virtualization.
10.15.12.2. About using virtual GPUs with OpenShift Virtualization
Some graphics processing unit (GPU) cards support the creation of virtual GPUs (vGPUs). OpenShift Virtualization can automatically create vGPUs and other mediated devices if an administrator provides configuration details in the HyperConverged
custom resource (CR). This automation is especially useful for large clusters.
Refer to your hardware vendor’s documentation for functionality and support details.
- Mediated device
- A physical device that is divided into one or more virtual devices. A vGPU is a type of mediated device (mdev); the performance of the physical GPU is divided among the virtual devices. You can assign mediated devices to one or more virtual machines (VMs), but the number of guests must be compatible with your GPU. Some GPUs do not support multiple guests.
10.15.12.2.1. Prerequisites
If your hardware vendor provides drivers, you installed them on the nodes where you want to create mediated devices.
- If you use NVIDIA cards, you installed the NVIDIA GRID driver.
10.15.12.2.2. Configuration overview
When configuring mediated devices, an administrator must complete the following tasks:
- Create the mediated devices.
- Expose the mediated devices to the cluster.
The HyperConverged
CR includes APIs that accomplish both tasks.
Creating mediated devices
# ... spec: mediatedDevicesConfiguration: mediatedDevicesTypes: 1 - <device_type> nodeMediatedDeviceTypes: 2 - mediatedDevicesTypes: 3 - <device_type> nodeSelector: 4 <node_selector_key>: <node_selector_value> # ...
- 1
- Required: Configures global settings for the cluster.
- 2
- Optional: Overrides the global configuration for a specific node or group of nodes. Must be used with the global
mediatedDevicesTypes
configuration. - 3
- Required if you use
nodeMediatedDeviceTypes
. Overrides the globalmediatedDevicesTypes
configuration for the specified nodes. - 4
- Required if you use
nodeMediatedDeviceTypes
. Must include akey:value
pair.
Exposing mediated devices to the cluster
# ... permittedHostDevices: mediatedDevices: - mdevNameSelector: GRID T4-2Q 1 resourceName: nvidia.com/GRID_T4-2Q 2 # ...
- 1
- Exposes the mediated devices that map to this value on the host.Note
You can see the mediated device types that your device supports by viewing the contents of
/sys/bus/pci/devices/<slot>:<bus>:<domain>.<function>/mdev_supported_types/<type>/name
, substituting the correct values for your system.For example, the name file for the
nvidia-231
type contains the selector stringGRID T4-2Q
. UsingGRID T4-2Q
as themdevNameSelector
value allows nodes to use thenvidia-231
type. - 2
- The
resourceName
should match that allocated on the node. Find theresourceName
by using the following command:$ oc get $NODE -o json \ | jq '.status.allocatable \ | with_entries(select(.key | startswith("nvidia.com/"))) \ | with_entries(select(.value != "0"))'
10.15.12.2.3. How vGPUs are assigned to nodes
For each physical device, OpenShift Virtualization configures the following values:
- A single mdev type.
-
The maximum number of instances of the selected
mdev
type.
The cluster architecture affects how devices are created and assigned to nodes.
- Large cluster with multiple cards per node
On nodes with multiple cards that can support similar vGPU types, the relevant device types are created in a round-robin manner. For example:
# ... mediatedDevicesConfiguration: mediatedDevicesTypes: - nvidia-222 - nvidia-228 - nvidia-105 - nvidia-108 # ...
In this scenario, each node has two cards, both of which support the following vGPU types:
nvidia-105 # ... nvidia-108 nvidia-217 nvidia-299 # ...
On each node, OpenShift Virtualization creates the following vGPUs:
- 16 vGPUs of type nvidia-105 on the first card.
- 2 vGPUs of type nvidia-108 on the second card.
- One node has a single card that supports more than one requested vGPU type
OpenShift Virtualization uses the supported type that comes first on the
mediatedDevicesTypes
list.For example, the card on a node card supports
nvidia-223
andnvidia-224
. The followingmediatedDevicesTypes
list is configured:# ... mediatedDevicesConfiguration: mediatedDevicesTypes: - nvidia-22 - nvidia-223 - nvidia-224 # ...
In this example, OpenShift Virtualization uses the
nvidia-223
type.
10.15.12.2.4. About changing and removing mediated devices
The cluster’s mediated device configuration can be updated with OpenShift Virtualization by:
-
Editing the
HyperConverged
CR and change the contents of themediatedDevicesTypes
stanza. -
Changing the node labels that match the
nodeMediatedDeviceTypes
node selector. Removing the device information from the
spec.mediatedDevicesConfiguration
andspec.permittedHostDevices
stanzas of theHyperConverged
CR.NoteIf you remove the device information from the
spec.permittedHostDevices
stanza without also removing it from thespec.mediatedDevicesConfiguration
stanza, you cannot create a new mediated device type on the same node. To properly remove mediated devices, remove the device information from both stanzas.
Depending on the specific changes, these actions cause OpenShift Virtualization to reconfigure mediated devices or remove them from the cluster nodes.
10.15.12.2.5. Preparing hosts for mediated devices
You must enable the Input-Output Memory Management Unit (IOMMU) driver before you can configure mediated devices.
10.15.12.2.5.1. Adding kernel arguments to enable the IOMMU driver
To enable the IOMMU (Input-Output Memory Management Unit) driver in the kernel, create the MachineConfig
object and add the kernel arguments.
Prerequisites
- Administrative privilege to a working OpenShift Container Platform cluster.
- Intel or AMD CPU hardware.
- Intel Virtualization Technology for Directed I/O extensions or AMD IOMMU in the BIOS (Basic Input/Output System) is enabled.
Procedure
Create a
MachineConfig
object that identifies the kernel argument. The following example shows a kernel argument for an Intel CPU.apiVersion: machineconfiguration.openshift.io/v1 kind: MachineConfig metadata: labels: machineconfiguration.openshift.io/role: worker 1 name: 100-worker-iommu 2 spec: config: ignition: version: 3.2.0 kernelArguments: - intel_iommu=on 3 # ...
Create the new
MachineConfig
object:$ oc create -f 100-worker-kernel-arg-iommu.yaml
Verification
Verify that the new
MachineConfig
object was added.$ oc get MachineConfig
10.15.12.2.6. Adding and removing mediated devices
You can add or remove mediated devices.
10.15.12.2.6.1. Creating and exposing mediated devices
You can expose and create mediated devices such as virtual GPUs (vGPUs) by editing the HyperConverged
custom resource (CR).
Prerequisites
- You enabled the IOMMU (Input-Output Memory Management Unit) driver.
Procedure
Edit the
HyperConverged
CR in your default editor by running the following command:$ oc edit hyperconverged kubevirt-hyperconverged -n openshift-cnv
Add the mediated device information to the
HyperConverged
CRspec
, ensuring that you include themediatedDevicesConfiguration
andpermittedHostDevices
stanzas. For example:Example configuration file
apiVersion: hco.kubevirt.io/v1 kind: HyperConverged metadata: name: kubevirt-hyperconverged namespace: openshift-cnv spec: mediatedDevicesConfiguration: <.> mediatedDevicesTypes: <.> - nvidia-231 nodeMediatedDeviceTypes: <.> - mediatedDevicesTypes: <.> - nvidia-233 nodeSelector: kubernetes.io/hostname: node-11.redhat.com permittedHostDevices: <.> mediatedDevices: - mdevNameSelector: GRID T4-2Q resourceName: nvidia.com/GRID_T4-2Q - mdevNameSelector: GRID T4-8Q resourceName: nvidia.com/GRID_T4-8Q # ...
<.> Creates mediated devices. <.> Required: Global
mediatedDevicesTypes
configuration. <.> Optional: Overrides the global configuration for specific nodes. <.> Required if you usenodeMediatedDeviceTypes
. <.> Exposes mediated devices to the cluster.- Save your changes and exit the editor.
Verification
You can verify that a device was added to a specific node by running the following command:
$ oc describe node <node_name>
10.15.12.2.6.2. Removing mediated devices from the cluster using the CLI
To remove a mediated device from the cluster, delete the information for that device from the HyperConverged
custom resource (CR).
Procedure
Edit the
HyperConverged
CR in your default editor by running the following command:$ oc edit hyperconverged kubevirt-hyperconverged -n openshift-cnv
Remove the device information from the
spec.mediatedDevicesConfiguration
andspec.permittedHostDevices
stanzas of theHyperConverged
CR. Removing both entries ensures that you can later create a new mediated device type on the same node. For example:Example configuration file
apiVersion: hco.kubevirt.io/v1 kind: HyperConverged metadata: name: kubevirt-hyperconverged namespace: openshift-cnv spec: mediatedDevicesConfiguration: mediatedDevicesTypes: 1 - nvidia-231 permittedHostDevices: mediatedDevices: 2 - mdevNameSelector: GRID T4-2Q resourceName: nvidia.com/GRID_T4-2Q
- Save your changes and exit the editor.
10.15.12.3. Using mediated devices
A vGPU is a type of mediated device; the performance of the physical GPU is divided among the virtual devices. You can assign mediated devices to one or more virtual machines.
10.15.12.3.1. Assigning a mediated device to a virtual machine
Assign mediated devices such as virtual GPUs (vGPUs) to virtual machines.
Prerequisites
-
The mediated device is configured in the
HyperConverged
custom resource.
Procedure
Assign the mediated device to a virtual machine (VM) by editing the
spec.domain.devices.gpus
stanza of theVirtualMachine
manifest:Example virtual machine manifest
apiVersion: kubevirt.io/v1 kind: VirtualMachine spec: domain: devices: gpus: - deviceName: nvidia.com/TU104GL_Tesla_T4 1 name: gpu1 2 - deviceName: nvidia.com/GRID_T4-1Q name: gpu2
Verification
To verify that the device is available from the virtual machine, run the following command, substituting
<device_name>
with thedeviceName
value from theVirtualMachine
manifest:$ lspci -nnk | grep <device_name>
10.15.12.4. Additional resources
10.15.13. Enabling descheduler evictions on virtual machines
You can use the descheduler to evict pods so that the pods can be rescheduled onto more appropriate nodes. If the pod is a virtual machine, the pod eviction causes the virtual machine to be live migrated to another node.
Descheduler eviction for virtual machines is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.
10.15.13.1. Descheduler profiles
Use the Technology Preview DevPreviewLongLifecycle
profile to enable the descheduler on a virtual machine. This is the only descheduler profile currently available for OpenShift Virtualization. To ensure proper scheduling, create VMs with CPU and memory requests for the expected load.
DevPreviewLongLifecycle
This profile balances resource usage between nodes and enables the following strategies:
-
RemovePodsHavingTooManyRestarts
: removes pods whose containers have been restarted too many times and pods where the sum of restarts over all containers (including Init Containers) is more than 100. Restarting the VM guest operating system does not increase this count. LowNodeUtilization
: evicts pods from overutilized nodes when there are any underutilized nodes. The destination node for the evicted pod will be determined by the scheduler.- A node is considered underutilized if its usage is below 20% for all thresholds (CPU, memory, and number of pods).
- A node is considered overutilized if its usage is above 50% for any of the thresholds (CPU, memory, and number of pods).
-
10.15.13.2. Installing the descheduler
The descheduler is not available by default. To enable the descheduler, you must install the Kube Descheduler Operator from OperatorHub and enable one or more descheduler profiles.
By default, the descheduler runs in predictive mode, which means that it only simulates pod evictions. You must change the mode to automatic for the descheduler to perform the pod evictions.
If you have enabled hosted control planes in your cluster, set a custom priority threshold to lower the chance that pods in the hosted control plane namespaces are evicted. Set the priority threshold class name to hypershift-control-plane
, because it has the lowest priority value (100000000
) of the hosted control plane priority classes.
Prerequisites
-
You are logged in to OpenShift Container Platform as a user with the
cluster-admin
role. - Access to the OpenShift Container Platform web console.
Procedure
- Log in to the OpenShift Container Platform web console.
Create the required namespace for the Kube Descheduler Operator.
-
Navigate to Administration
Namespaces and click Create Namespace. -
Enter
openshift-kube-descheduler-operator
in the Name field, enteropenshift.io/cluster-monitoring=true
in the Labels field to enable descheduler metrics, and click Create.
-
Navigate to Administration
Install the Kube Descheduler Operator.
-
Navigate to Operators
OperatorHub. - Type Kube Descheduler Operator into the filter box.
- Select the Kube Descheduler Operator and click Install.
- On the Install Operator page, select A specific namespace on the cluster. Select openshift-kube-descheduler-operator from the drop-down menu.
- Adjust the values for the Update Channel and Approval Strategy to the desired values.
- Click Install.
-
Navigate to Operators
Create a descheduler instance.
-
From the Operators
Installed Operators page, click the Kube Descheduler Operator. - Select the Kube Descheduler tab and click Create KubeDescheduler.
Edit the settings as necessary.
- To evict pods instead of simulating the evictions, change the Mode field to Automatic.
Expand the Profiles section and select
DevPreviewLongLifecycle
. TheAffinityAndTaints
profile is enabled by default.ImportantThe only profile currently available for OpenShift Virtualization is
DevPreviewLongLifecycle
.
-
From the Operators
You can also configure the profiles and settings for the descheduler later using the OpenShift CLI (oc
).
10.15.13.3. Enabling descheduler evictions on a virtual machine (VM)
After the descheduler is installed, you can enable descheduler evictions on your VM by adding an annotation to the VirtualMachine
custom resource (CR).
Prerequisites
-
Install the descheduler in the OpenShift Container Platform web console or OpenShift CLI (
oc
). - Ensure that the VM is not running.
Procedure
Before starting the VM, add the
descheduler.alpha.kubernetes.io/evict
annotation to theVirtualMachine
CR:apiVersion: kubevirt.io/v1 kind: VirtualMachine spec: template: metadata: annotations: descheduler.alpha.kubernetes.io/evict: "true"
If you did not already set the
DevPreviewLongLifecycle
profile in the web console during installation, specify theDevPreviewLongLifecycle
in thespec.profile
section of theKubeDescheduler
object:apiVersion: operator.openshift.io/v1 kind: KubeDescheduler metadata: name: cluster namespace: openshift-kube-descheduler-operator spec: deschedulingIntervalSeconds: 3600 profiles: - DevPreviewLongLifecycle mode: Predictive 1
- 1
- By default, the descheduler does not evict pods. To evict pods, set
mode
toAutomatic
.
The descheduler is now enabled on the VM.
10.15.13.4. Additional resources
10.16. Importing virtual machines
10.16.1. TLS certificates for data volume imports
10.16.1.1. Adding TLS certificates for authenticating data volume imports
TLS certificates for registry or HTTPS endpoints must be added to a config map to import data from these sources. This config map must be present in the namespace of the destination data volume.
Create the config map by referencing the relative file path for the TLS certificate.
Procedure
Ensure you are in the correct namespace. The config map can only be referenced by data volumes if it is in the same namespace.
$ oc get ns
Create the config map:
$ oc create configmap <configmap-name> --from-file=</path/to/file/ca.pem>
10.16.1.2. Example: Config map created from a TLS certificate
The following example is of a config map created from ca.pem
TLS certificate.
apiVersion: v1 kind: ConfigMap metadata: name: tls-certs data: ca.pem: | -----BEGIN CERTIFICATE----- ... <base64 encoded cert> ... -----END CERTIFICATE-----
10.16.2. Importing virtual machine images with data volumes
You can import an existing virtual machine image into your OpenShift Container Platform cluster storage. Using the Containerized Data Importer (CDI), you can import the image into a persistent volume claim (PVC) by using a data volume. OpenShift Virtualization uses one or more data volumes to automate the data import and the creation of an underlying PVC. You can attach a data volume to a virtual machine for persistent storage.
The virtual machine image can be hosted at an HTTP or HTTPS endpoint, or built into a container disk and stored in a container registry.
When you import a disk image into a PVC, the disk image is expanded to use the full storage capacity that is requested in the PVC. To use this space, the disk partitions and file system(s) in the virtual machine might need to be expanded.
The resizing procedure varies based on the operating system installed on the virtual machine. See the operating system documentation for details.
10.16.2.1. Prerequisites
- If the endpoint requires a TLS certificate, the certificate must be included in a config map in the same namespace as the data volume and referenced in the data volume configuration.
To import a container disk:
- You might need to prepare a container disk from a virtual machine image and store it in your container registry before importing it.
-
If the container registry does not have TLS, you must add the registry to the
insecureRegistries
field of theHyperConverged
custom resource before you can import a container disk from it.
- You might need to define a storage class or prepare CDI scratch space for this operation to complete successfully.
If you intend to import a virtual machine image into block storage with a data volume, you must have an available local block persistent volume.
10.16.2.2. CDI supported operations matrix
This matrix shows the supported CDI operations for content types against endpoints, and which of these operations requires scratch space.
Content types | HTTP | HTTPS | HTTP basic auth | Registry | Upload |
---|---|---|---|---|---|
KubeVirt (QCOW2) |
✓ QCOW2 |
✓ QCOW2** |
✓ QCOW2 |
✓ QCOW2* |
✓ QCOW2* |
KubeVirt (RAW) |
✓ RAW |
✓ RAW |
✓ RAW |
✓ RAW* |
✓ RAW* |
✓ Supported operation
□ Unsupported operation
* Requires scratch space
** Requires scratch space if a custom certificate authority is required
CDI now uses the OpenShift Container Platform cluster-wide proxy configuration.
10.16.2.3. About data volumes
DataVolume
objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). You can create a data volume as either a standalone resource or by using the dataVolumeTemplate
field in the virtual machine (VM) specification.
-
VM disk PVCs that are prepared by using standalone data volumes maintain an independent lifecycle from the VM. If you use the
dataVolumeTemplate
field in the VM specification to prepare the PVC, the PVC shares the same lifecycle as the VM.
10.16.2.4. Local block persistent volumes
If you intend to import a virtual machine image into block storage with a data volume, you must have an available local block persistent volume.
10.16.2.4.1. About block persistent volumes
A block persistent volume (PV) is a PV that is backed by a raw block device. These volumes do not have a file system and can provide performance benefits for virtual machines by reducing overhead.
Raw block volumes are provisioned by specifying volumeMode: Block
in the PV and persistent volume claim (PVC) specification.
10.16.2.4.2. Creating a local block persistent volume
If you intend to import a virtual machine image into block storage with a data volume, you must have an available local block persistent volume.
Create a local block persistent volume (PV) on a node by populating a file and mounting it as a loop device. You can then reference this loop device in a PV manifest as a Block
volume and use it as a block device for a virtual machine image.
Procedure
-
Log in as
root
to the node on which to create the local PV. This procedure usesnode01
for its examples. Create a file and populate it with null characters so that it can be used as a block device. The following example creates a file
loop10
with a size of 2Gb (20 100Mb blocks):$ dd if=/dev/zero of=<loop10> bs=100M count=20
Mount the
loop10
file as a loop device.$ losetup </dev/loop10>d3 <loop10> 1 2
Create a
PersistentVolume
manifest that references the mounted loop device.kind: PersistentVolume apiVersion: v1 metadata: name: <local-block-pv10> annotations: spec: local: path: </dev/loop10> 1 capacity: storage: <2Gi> volumeMode: Block 2 storageClassName: local 3 accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Delete nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - <node01> 4
Create the block PV.
# oc create -f <local-block-pv10.yaml>1
- 1
- The file name of the persistent volume created in the previous step.
10.16.2.5. Importing a virtual machine image into storage by using a data volume
You can import a virtual machine image into storage by using a data volume.
The virtual machine image can be hosted at an HTTP or HTTPS endpoint or the image can be built into a container disk and stored in a container registry.
You specify the data source for the image in a VirtualMachine
configuration file. When the virtual machine is created, the data volume with the virtual machine image is imported into storage.
Prerequisites
To import a virtual machine image you must have the following:
-
A virtual machine disk image in RAW, ISO, or QCOW2 format, optionally compressed by using
xz
orgz
. - An HTTP or HTTPS endpoint where the image is hosted, along with any authentication credentials needed to access the data source.
-
A virtual machine disk image in RAW, ISO, or QCOW2 format, optionally compressed by using
- To import a container disk, you must have a virtual machine image built into a container disk and stored in a container registry, along with any authentication credentials needed to access the data source.
- If the virtual machine must communicate with servers that use self-signed certificates or certificates not signed by the system CA bundle, you must create a config map in the same namespace as the data volume.
Procedure
If your data source requires authentication, create a
Secret
manifest, specifying the data source credentials, and save it asendpoint-secret.yaml
:apiVersion: v1 kind: Secret metadata: name: endpoint-secret 1 labels: app: containerized-data-importer type: Opaque data: accessKeyId: "" 2 secretKey: "" 3
Apply the
Secret
manifest:$ oc apply -f endpoint-secret.yaml
Edit the
VirtualMachine
manifest, specifying the data source for the virtual machine image you want to import, and save it asvm-fedora-datavolume.yaml
:apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: creationTimestamp: null labels: kubevirt.io/vm: vm-fedora-datavolume name: vm-fedora-datavolume 1 spec: dataVolumeTemplates: - metadata: creationTimestamp: null name: fedora-dv 2 spec: storage: volumeMode: Block 3 resources: requests: storage: 10Gi storageClassName: local source: 4 http: url: "https://mirror.arizona.edu/fedora/linux/releases/35/Cloud/x86_64/images/Fedora-Cloud-Base-35-1.2.x86_64.qcow2" 5 secretRef: endpoint-secret 6 certConfigMap: "" 7 # To use a registry source, uncomment the following lines and delete the preceding HTTP source block # registry: # url: "docker://kubevirt/fedora-cloud-container-disk-demo:latest" # secretRef: registry-secret 8 # certConfigMap: "" 9 status: {} running: true template: metadata: creationTimestamp: null labels: kubevirt.io/vm: vm-fedora-datavolume spec: domain: devices: disks: - disk: bus: virtio name: datavolumedisk1 machine: type: "" resources: requests: memory: 1.5Gi terminationGracePeriodSeconds: 180 volumes: - dataVolume: name: fedora-dv name: datavolumedisk1 status: {}
- 1
- Specify the name of the virtual machine.
- 2
- Specify the name of the data volume.
- 3
- The volume and access mode are detected automatically for known storage provisioners. Alternatively, you can specify
Block
. - 4 5
- Specify either the URL or the registry endpoint of the virtual machine image you want to import using the comment block. For example, if you want to use a registry source, you can comment out or delete the HTTP or HTTPS source block. Ensure that you replace the example values shown here with your own values.
- 6 8
- Specify the
Secret
name if you created aSecret
for the data source. - 7 9
- Optional: Specify a CA certificate config map.
Create the virtual machine:
$ oc create -f vm-fedora-datavolume.yaml
NoteThe
oc create
command creates the data volume and the virtual machine. The CDI controller creates an underlying PVC with the correct annotation and the import process begins. When the import is complete, the data volume status changes toSucceeded
. You can start the virtual machine.Data volume provisioning happens in the background, so there is no need to monitor the process.
Verification
The importer pod downloads the virtual machine image or container disk from the specified URL and stores it on the provisioned PV. View the status of the importer pod by running the following command:
$ oc get pods
Monitor the data volume until its status is
Succeeded
by running the following command:$ oc describe dv fedora-dv 1
- 1
- Specify the data volume name that you defined in the
VirtualMachine
manifest.
Verify that provisioning is complete and that the virtual machine has started by accessing its serial console:
$ virtctl console vm-fedora-datavolume
10.16.2.6. Additional resources
- Configure preallocation mode to improve write performance for data volume operations.
10.17. Cloning virtual machines
10.17.1. Enabling user permissions to clone data volumes across namespaces
The isolating nature of namespaces means that users cannot by default clone resources between namespaces.
To enable a user to clone a virtual machine to another namespace, a user with the cluster-admin
role must create a new cluster role. Bind this cluster role to a user to enable them to clone virtual machines to the destination namespace.
10.17.1.1. Prerequisites
-
Only a user with the
cluster-admin
role can create cluster roles.
10.17.1.2. About data volumes
DataVolume
objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). You can create a data volume as either a standalone resource or by using the dataVolumeTemplate
field in the virtual machine (VM) specification.
-
VM disk PVCs that are prepared by using standalone data volumes maintain an independent lifecycle from the VM. If you use the
dataVolumeTemplate
field in the VM specification to prepare the PVC, the PVC shares the same lifecycle as the VM.
10.17.1.3. Creating RBAC resources for cloning data volumes
Create a new cluster role that enables permissions for all actions for the datavolumes
resource.
Procedure
Create a
ClusterRole
manifest:apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: name: <datavolume-cloner> 1 rules: - apiGroups: ["cdi.kubevirt.io"] resources: ["datavolumes/source"] verbs: ["*"]
- 1
- Unique name for the cluster role.
Create the cluster role in the cluster:
$ oc create -f <datavolume-cloner.yaml> 1
- 1
- The file name of the
ClusterRole
manifest created in the previous step.
Create a
RoleBinding
manifest that applies to both the source and destination namespaces and references the cluster role created in the previous step.apiVersion: rbac.authorization.k8s.io/v1 kind: RoleBinding metadata: name: <allow-clone-to-user> 1 namespace: <Source namespace> 2 subjects: - kind: ServiceAccount name: default namespace: <Destination namespace> 3 roleRef: kind: ClusterRole name: datavolume-cloner 4 apiGroup: rbac.authorization.k8s.io
Create the role binding in the cluster:
$ oc create -f <datavolume-cloner.yaml> 1
- 1
- The file name of the
RoleBinding
manifest created in the previous step.
10.17.2. Cloning a virtual machine disk into a new data volume
You can clone the persistent volume claim (PVC) of a virtual machine disk into a new data volume by referencing the source PVC in your data volume configuration file.
Cloning operations between different volume modes are supported, such as cloning from a persistent volume (PV) with volumeMode: Block
to a PV with volumeMode: Filesystem
.
However, you can only clone between different volume modes if they are of the contentType: kubevirt
.
When you enable preallocation globally, or for a single data volume, the Containerized Data Importer (CDI) preallocates disk space during cloning. Preallocation enhances write performance. For more information, see Using preallocation for data volumes.
10.17.2.1. Prerequisites
- Users need additional permissions to clone the PVC of a virtual machine disk into another namespace.
10.17.2.2. About data volumes
DataVolume
objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). You can create a data volume as either a standalone resource or by using the dataVolumeTemplate
field in the virtual machine (VM) specification.
-
VM disk PVCs that are prepared by using standalone data volumes maintain an independent lifecycle from the VM. If you use the
dataVolumeTemplate
field in the VM specification to prepare the PVC, the PVC shares the same lifecycle as the VM.
10.17.2.3. Cloning the persistent volume claim of a virtual machine disk into a new data volume
You can clone a persistent volume claim (PVC) of an existing virtual machine disk into a new data volume. The new data volume can then be used for a new virtual machine.
When a data volume is created independently of a virtual machine, the lifecycle of the data volume is independent of the virtual machine. If the virtual machine is deleted, neither the data volume nor its associated PVC is deleted.
Prerequisites
- Determine the PVC of an existing virtual machine disk to use. You must power down the virtual machine that is associated with the PVC before you can clone it.
-
Install the OpenShift CLI (
oc
).
Procedure
- Examine the virtual machine disk you want to clone to identify the name and namespace of the associated PVC.
Create a YAML file for a data volume that specifies the name of the new data volume, the name and namespace of the source PVC, and the size of the new data volume.
For example:
apiVersion: cdi.kubevirt.io/v1beta1 kind: DataVolume metadata: name: <cloner-datavolume> 1 spec: source: pvc: namespace: "<source-namespace>" 2 name: "<my-favorite-vm-disk>" 3 pvc: accessModes: - ReadWriteOnce resources: requests: storage: <2Gi> 4
Start cloning the PVC by creating the data volume:
$ oc create -f <cloner-datavolume>.yaml
NoteData volumes prevent a virtual machine from starting before the PVC is prepared, so you can create a virtual machine that references the new data volume while the PVC clones.
10.17.2.4. CDI supported operations matrix
This matrix shows the supported CDI operations for content types against endpoints, and which of these operations requires scratch space.
Content types | HTTP | HTTPS | HTTP basic auth | Registry | Upload |
---|---|---|---|---|---|
KubeVirt (QCOW2) |
✓ QCOW2 |
✓ QCOW2** |
✓ QCOW2 |
✓ QCOW2* |
✓ QCOW2* |
KubeVirt (RAW) |
✓ RAW |
✓ RAW |
✓ RAW |
✓ RAW* |
✓ RAW* |
✓ Supported operation
□ Unsupported operation
* Requires scratch space
** Requires scratch space if a custom certificate authority is required
10.17.3. Cloning a virtual machine by using a data volume template
You can create a new virtual machine by cloning the persistent volume claim (PVC) of an existing VM. By including a dataVolumeTemplate
in your virtual machine configuration file, you create a new data volume from the original PVC.
Cloning operations between different volume modes are supported, such as cloning from a persistent volume (PV) with volumeMode: Block
to a PV with volumeMode: Filesystem
.
However, you can only clone between different volume modes if they are of the contentType: kubevirt
.
When you enable preallocation globally, or for a single data volume, the Containerized Data Importer (CDI) preallocates disk space during cloning. Preallocation enhances write performance. For more information, see Using preallocation for data volumes.
10.17.3.1. Prerequisites
- Users need additional permissions to clone the PVC of a virtual machine disk into another namespace.
10.17.3.2. About data volumes
DataVolume
objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). You can create a data volume as either a standalone resource or by using the dataVolumeTemplate
field in the virtual machine (VM) specification.
-
VM disk PVCs that are prepared by using standalone data volumes maintain an independent lifecycle from the VM. If you use the
dataVolumeTemplate
field in the VM specification to prepare the PVC, the PVC shares the same lifecycle as the VM.
10.17.3.3. Creating a new virtual machine from a cloned persistent volume claim by using a data volume template
You can create a virtual machine that clones the persistent volume claim (PVC) of an existing virtual machine into a data volume. Reference a dataVolumeTemplate
in the virtual machine manifest and the source
PVC is cloned to a data volume, which is then automatically used for the creation of the virtual machine.
When a data volume is created as part of the data volume template of a virtual machine, the lifecycle of the data volume is then dependent on the virtual machine. If the virtual machine is deleted, the data volume and associated PVC are also deleted.
Prerequisites
- Determine the PVC of an existing virtual machine disk to use. You must power down the virtual machine that is associated with the PVC before you can clone it.
-
Install the OpenShift CLI (
oc
).
Procedure
- Examine the virtual machine you want to clone to identify the name and namespace of the associated PVC.
Create a YAML file for a
VirtualMachine
object. The following virtual machine example clonesmy-favorite-vm-disk
, which is located in thesource-namespace
namespace. The2Gi
data volume calledfavorite-clone
is created frommy-favorite-vm-disk
.For example:
apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: labels: kubevirt.io/vm: vm-dv-clone name: vm-dv-clone 1 spec: running: false template: metadata: labels: kubevirt.io/vm: vm-dv-clone spec: domain: devices: disks: - disk: bus: virtio name: root-disk resources: requests: memory: 64M volumes: - dataVolume: name: favorite-clone name: root-disk dataVolumeTemplates: - metadata: name: favorite-clone spec: storage: accessModes: - ReadWriteOnce resources: requests: storage: 2Gi source: pvc: namespace: "source-namespace" name: "my-favorite-vm-disk"
- 1
- The virtual machine to create.
Create the virtual machine with the PVC-cloned data volume:
$ oc create -f <vm-clone-datavolumetemplate>.yaml
10.17.3.4. CDI supported operations matrix
This matrix shows the supported CDI operations for content types against endpoints, and which of these operations requires scratch space.
Content types | HTTP | HTTPS | HTTP basic auth | Registry | Upload |
---|---|---|---|---|---|
KubeVirt (QCOW2) |
✓ QCOW2 |
✓ QCOW2** |
✓ QCOW2 |
✓ QCOW2* |
✓ QCOW2* |
KubeVirt (RAW) |
✓ RAW |
✓ RAW |
✓ RAW |
✓ RAW* |
✓ RAW* |
✓ Supported operation
□ Unsupported operation
* Requires scratch space
** Requires scratch space if a custom certificate authority is required
10.17.4. Cloning a virtual machine disk into a new block storage persistent volume claim
You can clone the persistent volume claim (PVC) of a virtual machine disk into a new block PVC by referencing the source PVC in your clone target data volume configuration file.
Cloning operations between different volume modes are supported, such as cloning from a persistent volume (PV) with volumeMode: Block
to a PV with volumeMode: Filesystem
.
However, you can only clone between different volume modes if they are of the contentType: kubevirt
.
When you enable preallocation globally, or for a single data volume, the Containerized Data Importer (CDI) preallocates disk space during cloning. Preallocation enhances write performance. For more information, see Using preallocation for data volumes.
10.17.4.1. Prerequisites
- Users need additional permissions to clone the PVC of a virtual machine disk into another namespace.
10.17.4.2. About data volumes
DataVolume
objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). You can create a data volume as either a standalone resource or by using the dataVolumeTemplate
field in the virtual machine (VM) specification.
-
VM disk PVCs that are prepared by using standalone data volumes maintain an independent lifecycle from the VM. If you use the
dataVolumeTemplate
field in the VM specification to prepare the PVC, the PVC shares the same lifecycle as the VM.
10.17.4.3. About block persistent volumes
A block persistent volume (PV) is a PV that is backed by a raw block device. These volumes do not have a file system and can provide performance benefits for virtual machines by reducing overhead.
Raw block volumes are provisioned by specifying volumeMode: Block
in the PV and persistent volume claim (PVC) specification.
10.17.4.4. Creating a local block persistent volume
If you intend to import a virtual machine image into block storage with a data volume, you must have an available local block persistent volume.
Create a local block persistent volume (PV) on a node by populating a file and mounting it as a loop device. You can then reference this loop device in a PV manifest as a Block
volume and use it as a block device for a virtual machine image.
Procedure
-
Log in as
root
to the node on which to create the local PV. This procedure usesnode01
for its examples. Create a file and populate it with null characters so that it can be used as a block device. The following example creates a file
loop10
with a size of 2Gb (20 100Mb blocks):$ dd if=/dev/zero of=<loop10> bs=100M count=20
Mount the
loop10
file as a loop device.$ losetup </dev/loop10>d3 <loop10> 1 2
Create a
PersistentVolume
manifest that references the mounted loop device.kind: PersistentVolume apiVersion: v1 metadata: name: <local-block-pv10> annotations: spec: local: path: </dev/loop10> 1 capacity: storage: <2Gi> volumeMode: Block 2 storageClassName: local 3 accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Delete nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - <node01> 4
Create the block PV.
# oc create -f <local-block-pv10.yaml>1
- 1
- The file name of the persistent volume created in the previous step.
10.17.4.5. Cloning the persistent volume claim of a virtual machine disk into a new data volume
You can clone a persistent volume claim (PVC) of an existing virtual machine disk into a new data volume. The new data volume can then be used for a new virtual machine.
When a data volume is created independently of a virtual machine, the lifecycle of the data volume is independent of the virtual machine. If the virtual machine is deleted, neither the data volume nor its associated PVC is deleted.
Prerequisites
- Determine the PVC of an existing virtual machine disk to use. You must power down the virtual machine that is associated with the PVC before you can clone it.
-
Install the OpenShift CLI (
oc
). - At least one available block persistent volume (PV) that is the same size as or larger than the source PVC.
Procedure
- Examine the virtual machine disk you want to clone to identify the name and namespace of the associated PVC.
Create a YAML file for a data volume that specifies the name of the new data volume, the name and namespace of the source PVC,
volumeMode: Block
so that an available block PV is used, and the size of the new data volume.For example:
apiVersion: cdi.kubevirt.io/v1beta1 kind: DataVolume metadata: name: <cloner-datavolume> 1 spec: source: pvc: namespace: "<source-namespace>" 2 name: "<my-favorite-vm-disk>" 3 pvc: accessModes: - ReadWriteOnce resources: requests: storage: <2Gi> 4 volumeMode: Block 5
- 1
- The name of the new data volume.
- 2
- The namespace where the source PVC exists.
- 3
- The name of the source PVC.
- 4
- The size of the new data volume. You must allocate enough space, or the cloning operation fails. The size must be the same as or larger than the source PVC.
- 5
- Specifies that the destination is a block PV
Start cloning the PVC by creating the data volume:
$ oc create -f <cloner-datavolume>.yaml
NoteData volumes prevent a virtual machine from starting before the PVC is prepared, so you can create a virtual machine that references the new data volume while the PVC clones.
10.17.4.6. CDI supported operations matrix
This matrix shows the supported CDI operations for content types against endpoints, and which of these operations requires scratch space.
Content types | HTTP | HTTPS | HTTP basic auth | Registry | Upload |
---|---|---|---|---|---|
KubeVirt (QCOW2) |
✓ QCOW2 |
✓ QCOW2** |
✓ QCOW2 |
✓ QCOW2* |
✓ QCOW2* |
KubeVirt (RAW) |
✓ RAW |
✓ RAW |
✓ RAW |
✓ RAW* |
✓ RAW* |
✓ Supported operation
□ Unsupported operation
* Requires scratch space
** Requires scratch space if a custom certificate authority is required
10.18. Virtual machine networking
10.18.1. Configuring the virtual machine for the default pod network
You can connect a virtual machine to the default internal pod network by configuring its network interface to use the masquerade
binding mode.
Traffic on the virtual Network Interface Cards (vNICs) that are attached to the default pod network is interrupted during live migration.
10.18.1.1. Configuring masquerade mode from the command line
You can use masquerade mode to hide a virtual machine’s outgoing traffic behind the pod IP address. Masquerade mode uses Network Address Translation (NAT) to connect virtual machines to the pod network backend through a Linux bridge.
Enable masquerade mode and allow traffic to enter the virtual machine by editing your virtual machine configuration file.
Prerequisites
- The virtual machine must be configured to use DHCP to acquire IPv4 addresses. The examples below are configured to use DHCP.
Procedure
Edit the
interfaces
spec of your virtual machine configuration file:kind: VirtualMachine spec: domain: devices: interfaces: - name: default masquerade: {} 1 ports: 2 - port: 80 networks: - name: default pod: {}
- 1
- Connect using masquerade mode.
- 2
- Optional: List the ports that you want to expose from the virtual machine, each specified by the
port
field. Theport
value must be a number between 0 and 65536. When theports
array is not used, all ports in the valid range are open to incoming traffic. In this example, incoming traffic is allowed on port80
.
NotePorts 49152 and 49153 are reserved for use by the libvirt platform and all other incoming traffic to these ports is dropped.
Create the virtual machine:
$ oc create -f <vm-name>.yaml
10.18.1.2. Configuring masquerade mode with dual-stack (IPv4 and IPv6)
You can configure a new virtual machine (VM) to use both IPv6 and IPv4 on the default pod network by using cloud-init.
The Network.pod.vmIPv6NetworkCIDR
field in the virtual machine instance configuration determines the static IPv6 address of the VM and the gateway IP address. These are used by the virt-launcher pod to route IPv6 traffic to the virtual machine and are not used externally. The Network.pod.vmIPv6NetworkCIDR
field specifies an IPv6 address block in Classless Inter-Domain Routing (CIDR) notation. The default value is fd10:0:2::2/120
. You can edit this value based on your network requirements.
When the virtual machine is running, incoming and outgoing traffic for the virtual machine is routed to both the IPv4 address and the unique IPv6 address of the virt-launcher pod. The virt-launcher pod then routes the IPv4 traffic to the DHCP address of the virtual machine, and the IPv6 traffic to the statically set IPv6 address of the virtual machine.
Prerequisites
- The OpenShift Container Platform cluster must use the OVN-Kubernetes Container Network Interface (CNI) network plugin configured for dual-stack.
Procedure
In a new virtual machine configuration, include an interface with
masquerade
and configure the IPv6 address and default gateway by using cloud-init.apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: name: example-vm-ipv6 # ... interfaces: - name: default masquerade: {} 1 ports: - port: 80 2 networks: - name: default pod: {} volumes: - cloudInitNoCloud: networkData: | version: 2 ethernets: eth0: dhcp4: true addresses: [ fd10:0:2::2/120 ] 3 gateway6: fd10:0:2::1 4
- 1
- Connect using masquerade mode.
- 2
- Allows incoming traffic on port 80 to the virtual machine.
- 3
- The static IPv6 address as determined by the
Network.pod.vmIPv6NetworkCIDR
field in the virtual machine instance configuration. The default value isfd10:0:2::2/120
. - 4
- The gateway IP address as determined by the
Network.pod.vmIPv6NetworkCIDR
field in the virtual machine instance configuration. The default value isfd10:0:2::1
.
Create the virtual machine in the namespace:
$ oc create -f example-vm-ipv6.yaml
Verification
- To verify that IPv6 has been configured, start the virtual machine and view the interface status of the virtual machine instance to ensure it has an IPv6 address:
$ oc get vmi <vmi-name> -o jsonpath="{.status.interfaces[*].ipAddresses}"
10.18.1.3. About jumbo frames support
When using the OVN-Kubernetes CNI plugin, you can send unfragmented jumbo frame packets between two virtual machines (VMs) that are connected on the default pod network. Jumbo frames have a maximum transmission unit (MTU) value greater than 1500 bytes.
The VM automatically gets the MTU value of the cluster network, set by the cluster administrator, in one of the following ways:
-
libvirt
: If the guest OS has the latest version of the VirtIO driver that can interpret incoming data via a Peripheral Component Interconnect (PCI) config register in the emulated device. - DHCP: If the guest DHCP client can read the MTU value from the DHCP server response.
For Windows VMs that do not have a VirtIO driver, you must set the MTU manually by using netsh
or a similar tool. This is because the Windows DHCP client does not read the MTU value.
Additional resources
10.18.2. Creating a service to expose a virtual machine
You can expose a virtual machine within the cluster or outside the cluster by using a Service
object.
10.18.2.1. About services
A Kubernetes service exposes network access for clients to an application running on a set of pods. Services offer abstraction, load balancing, and, in the case of NodePort and LoadBalancer, exposure to the outside world.
Services can be exposed in the VirtualMachine details spec.type
in the Service
object:
- ClusterIP
-
Exposes the service on an internal IP address and as a DNS name to other applications within the cluster. A single service can map to multiple virtual machines. When a client tries to connect to the service, the client’s request is load balanced among available backends.
ClusterIP
is the default servicetype
. - NodePort
-
Exposes the service on the same port of each selected node in the cluster.
NodePort
makes a service accessible from outside the cluster. - LoadBalancer
- Creates an external load balancer in the current cloud (if supported) and assigns a fixed, external IP address to the service.
For on-premise clusters, you can configure a load-balancing service by deploying the MetalLB Operator.
Additional resources
10.18.2.1.1. Dual-stack support
If IPv4 and IPv6 dual-stack networking is enabled for your cluster, you can create a service that uses IPv4, IPv6, or both, by defining the spec.ipFamilyPolicy
and the spec.ipFamilies
fields in the Service
object.
The spec.ipFamilyPolicy
field can be set to one of the following values:
- SingleStack
- The control plane assigns a cluster IP address for the service based on the first configured service cluster IP range.
- PreferDualStack
- The control plane assigns both IPv4 and IPv6 cluster IP addresses for the service on clusters that have dual-stack configured.
- RequireDualStack
-
This option fails for clusters that do not have dual-stack networking enabled. For clusters that have dual-stack configured, the behavior is the same as when the value is set to
PreferDualStack
. The control plane allocates cluster IP addresses from both IPv4 and IPv6 address ranges.
You can define which IP family to use for single-stack or define the order of IP families for dual-stack by setting the spec.ipFamilies
field to one of the following array values:
-
[IPv4]
-
[IPv6]
-
[IPv4, IPv6]
-
[IPv6, IPv4]
10.18.2.2. Exposing a virtual machine as a service
Create a ClusterIP
, NodePort
, or LoadBalancer
service to connect to a running virtual machine (VM) from within or outside the cluster.
Procedure
Edit the
VirtualMachine
manifest to add the label for service creation:apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: name: vm-ephemeral namespace: example-namespace spec: running: false template: metadata: labels: special: key 1 # ...
- 1
- Add the label
special: key
in thespec.template.metadata.labels
section.
NoteLabels on a virtual machine are passed through to the pod. The
special: key
label must match the label in thespec.selector
attribute of theService
manifest.-
Save the
VirtualMachine
manifest file to apply your changes. Create a
Service
manifest to expose the VM:apiVersion: v1 kind: Service metadata: name: vmservice 1 namespace: example-namespace 2 spec: externalTrafficPolicy: Cluster 3 ports: - nodePort: 30000 4 port: 27017 protocol: TCP targetPort: 22 5 selector: special: key 6 type: NodePort 7
- 1
- The name of the
Service
object. - 2
- The namespace where the
Service
object resides. This must match themetadata.namespace
field of theVirtualMachine
manifest. - 3
- Optional: Specifies how the nodes distribute service traffic that is received on external IP addresses. This only applies to
NodePort
andLoadBalancer
service types. The default value isCluster
which routes traffic evenly to all cluster endpoints. - 4
- Optional: When set, the
nodePort
value must be unique across all services. If not specified, a value in the range above30000
is dynamically allocated. - 5
- Optional: The VM port to be exposed by the service. It must reference an open port if a port list is defined in the VM manifest. If
targetPort
is not specified, it takes the same value asport
. - 6
- The reference to the label that you added in the
spec.template.metadata.labels
stanza of theVirtualMachine
manifest. - 7
- The type of service. Possible values are
ClusterIP
,NodePort
andLoadBalancer
.
-
Save the
Service
manifest file. Create the service by running the following command:
$ oc create -f <service_name>.yaml
- Start the VM. If the VM is already running, restart it.
Verification
Query the
Service
object to verify that it is available:$ oc get service -n example-namespace
Example output for
ClusterIP
serviceNAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE vmservice ClusterIP 172.30.3.149 <none> 27017/TCP 2m
Example output for
NodePort
serviceNAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE vmservice NodePort 172.30.232.73 <none> 27017:30000/TCP 5m
Example output for
LoadBalancer
serviceNAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE vmservice LoadBalancer 172.30.27.5 172.29.10.235,172.29.10.235 27017:31829/TCP 5s
Choose the appropriate method to connect to the virtual machine:
For a
ClusterIP
service, connect to the VM from within the cluster by using the service IP address and the service port. For example:$ ssh fedora@172.30.3.149 -p 27017
For a
NodePort
service, connect to the VM by specifying the node IP address and the node port outside the cluster network. For example:$ ssh fedora@$NODE_IP -p 30000
-
For a
LoadBalancer
service, use thevinagre
client to connect to your virtual machine by using the public IP address and port. External ports are dynamically allocated.
10.18.2.3. Additional resources
10.18.3. Connecting a virtual machine to a Linux bridge network
By default, OpenShift Virtualization is installed with a single, internal pod network.
You must create a Linux bridge network attachment definition (NAD) in order to connect to additional networks.
To attach a virtual machine to an additional network:
- Create a Linux bridge node network configuration policy.
- Create a Linux bridge network attachment definition.
- Configure the virtual machine, enabling the virtual machine to recognize the network attachment definition.
For more information about scheduling, interface types, and other node networking activities, see the node networking section.
10.18.3.1. Connecting to the network through the network attachment definition
10.18.3.1.1. Creating a Linux bridge node network configuration policy
Use a NodeNetworkConfigurationPolicy
manifest YAML file to create the Linux bridge.
Prerequisites
- You have installed the Kubernetes NMState Operator.
Procedure
Create the
NodeNetworkConfigurationPolicy
manifest. This example includes sample values that you must replace with your own information.apiVersion: nmstate.io/v1 kind: NodeNetworkConfigurationPolicy metadata: name: br1-eth1-policy 1 spec: desiredState: interfaces: - name: br1 2 description: Linux bridge with eth1 as a port 3 type: linux-bridge 4 state: up 5 ipv4: enabled: false 6 bridge: options: stp: enabled: false 7 port: - name: eth1 8
- 1
- Name of the policy.
- 2
- Name of the interface.
- 3
- Optional: Human-readable description of the interface.
- 4
- The type of interface. This example creates a bridge.
- 5
- The requested state for the interface after creation.
- 6
- Disables IPv4 in this example.
- 7
- Disables STP in this example.
- 8
- The node NIC to which the bridge is attached.
10.18.3.2. Creating a Linux bridge network attachment definition
Configuring IP address management (IPAM) in a network attachment definition for virtual machines is not supported.
10.18.3.2.1. Creating a Linux bridge network attachment definition in the web console
You can create network attachment definitions to provide layer-2 networking to pods and virtual machines.
A Linux bridge network attachment definition is the most efficient method for connecting a virtual machine to a VLAN.
Procedure
-
In the web console, click Networking
NetworkAttachmentDefinitions. Click Create Network Attachment Definition.
NoteThe network attachment definition must be in the same namespace as the pod or virtual machine.
- Enter a unique Name and optional Description.
- Select CNV Linux bridge from the Network Type list.
- Enter the name of the bridge in the Bridge Name field.
- Optional: If the resource has VLAN IDs configured, enter the ID numbers in the VLAN Tag Number field.
- Optional: Select MAC Spoof Check to enable MAC spoof filtering. This feature provides security against a MAC spoofing attack by allowing only a single MAC address to exit the pod.
- Click Create.
10.18.3.2.2. Creating a Linux bridge network attachment definition in the CLI
As a network administrator, you can configure a network attachment definition of type cnv-bridge
to provide layer-2 networking to pods and virtual machines.
Prerequisites
-
The node must support nftables and the
nft
binary must be deployed to enable MAC spoof check.
Procedure
- Create a network attachment definition in the same namespace as the virtual machine.
Add the virtual machine to the network attachment definition, as in the following example:
apiVersion: "k8s.cni.cncf.io/v1" kind: NetworkAttachmentDefinition metadata: name: <bridge-network> 1 annotations: k8s.v1.cni.cncf.io/resourceName: bridge.network.kubevirt.io/<bridge-interface> 2 spec: config: '{ "cniVersion": "0.3.1", "name": "<bridge-network>", 3 "type": "cnv-bridge", 4 "bridge": "<bridge-interface>", 5 "macspoofchk": true, 6 "vlan": 100, 7 "preserveDefaultVlan": false 8 }'
- 1
- The name for the
NetworkAttachmentDefinition
object. - 2
- Optional: Annotation key-value pair for node selection, where
bridge-interface
must match the name of a bridge configured on some nodes. If you add this annotation to your network attachment definition, your virtual machine instances will only run on the nodes that have thebridge-interface
bridge connected. - 3
- The name for the configuration. It is recommended to match the configuration name to the
name
value of the network attachment definition. - 4
- The actual name of the Container Network Interface (CNI) plugin that provides the network for this network attachment definition. Do not change this field unless you want to use a different CNI.
- 5
- The name of the Linux bridge configured on the node.
- 6
- Optional: Flag to enable MAC spoof check. When set to
true
, you cannot change the MAC address of the pod or guest interface. This attribute provides security against a MAC spoofing attack by allowing only a single MAC address to exit the pod. - 7
- Optional: The VLAN tag. No additional VLAN configuration is required on the node network configuration policy.
- 8
- Optional: Indicates whether the VM connects to the bridge through the default VLAN. The default value is
true
.
NoteA Linux bridge network attachment definition is the most efficient method for connecting a virtual machine to a VLAN.
Create the network attachment definition:
$ oc create -f <network-attachment-definition.yaml> 1
- 1
- Where
<network-attachment-definition.yaml>
is the file name of the network attachment definition manifest.
Verification
Verify that the network attachment definition was created by running the following command:
$ oc get network-attachment-definition <bridge-network>
10.18.3.3. Configuring the virtual machine for a Linux bridge network
10.18.3.3.1. Creating a NIC for a virtual machine in the web console
Create and attach additional NICs to a virtual machine from the web console.
Prerequisites
- A network attachment definition must be available.
Procedure
-
In the correct project in the OpenShift Container Platform console, click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
-
Click Configuration
Network interfaces to view the NICs already attached to the virtual machine. - Click Add Network Interface to create a new slot in the list.
- Select a network attachment definition from the Network list for the additional network.
- Fill in the Name, Model, Type, and MAC Address for the new NIC.
- Click Save to save and attach the NIC to the virtual machine.
10.18.3.3.2. Networking fields
Name | Description |
---|---|
Name | Name for the network interface controller. |
Model | Indicates the model of the network interface controller. Supported values are e1000e and virtio. |
Network | List of available network attachment definitions. |
Type | List of available binding methods. Select the binding method suitable for the network interface:
|
MAC Address | MAC address for the network interface controller. If a MAC address is not specified, one is assigned automatically. |
10.18.3.3.3. Attaching a virtual machine to an additional network in the CLI
Attach a virtual machine to an additional network by adding a bridge interface and specifying a network attachment definition in the virtual machine configuration.
This procedure uses a YAML file to demonstrate editing the configuration and applying the updated file to the cluster. You can alternatively use the oc edit <object> <name>
command to edit an existing virtual machine.
Prerequisites
- Shut down the virtual machine before editing the configuration. If you edit a running virtual machine, you must restart the virtual machine for the changes to take effect.
Procedure
- Create or edit a configuration of a virtual machine that you want to connect to the bridge network.
Add the bridge interface to the
spec.template.spec.domain.devices.interfaces
list and the network attachment definition to thespec.template.spec.networks
list. This example adds a bridge interface calledbridge-net
that connects to thea-bridge-network
network attachment definition:apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: name: <example-vm> spec: template: spec: domain: devices: interfaces: - masquerade: {} name: <default> - bridge: {} name: <bridge-net> 1 # ... networks: - name: <default> pod: {} - name: <bridge-net> 2 multus: networkName: <network-namespace>/<a-bridge-network> 3 # ...
- 1
- The name of the bridge interface.
- 2
- The name of the network. This value must match the
name
value of the correspondingspec.template.spec.domain.devices.interfaces
entry. - 3
- The name of the network attachment definition, prefixed by the namespace where it exists. The namespace must be either the
default
namespace or the same namespace where the VM is to be created. In this case,multus
is used. Multus is a cloud network interface (CNI) plugin that allows multiple CNIs to exist so that a pod or virtual machine can use the interfaces it needs.
Apply the configuration:
$ oc apply -f <example-vm.yaml>
- Optional: If you edited a running virtual machine, you must restart it for the changes to take effect.
10.18.3.4. Next steps
10.18.4. Connecting a virtual machine to an SR-IOV network
You can connect a virtual machine (VM) to a Single Root I/O Virtualization (SR-IOV) network by performing the following steps:
- Configure an SR-IOV network device.
- Configure an SR-IOV network.
- Connect the VM to the SR-IOV network.
10.18.4.1. Prerequisites
- You must have enabled global SR-IOV and VT-d settings in the firmware for the host.
- You must have installed the SR-IOV Network Operator.
10.18.4.2. Configuring SR-IOV network devices
The SR-IOV Network Operator adds the SriovNetworkNodePolicy.sriovnetwork.openshift.io
CustomResourceDefinition to OpenShift Container Platform. You can configure an SR-IOV network device by creating a SriovNetworkNodePolicy custom resource (CR).
When applying the configuration specified in a SriovNetworkNodePolicy
object, the SR-IOV Operator might drain the nodes, and in some cases, reboot nodes.
It might take several minutes for a configuration change to apply.
Prerequisites
-
You installed the OpenShift CLI (
oc
). -
You have access to the cluster as a user with the
cluster-admin
role. - You have installed the SR-IOV Network Operator.
- You have enough available nodes in your cluster to handle the evicted workload from drained nodes.
- You have not selected any control plane nodes for SR-IOV network device configuration.
Procedure
Create an
SriovNetworkNodePolicy
object, and then save the YAML in the<name>-sriov-node-network.yaml
file. Replace<name>
with the name for this configuration.apiVersion: sriovnetwork.openshift.io/v1 kind: SriovNetworkNodePolicy metadata: name: <name> 1 namespace: openshift-sriov-network-operator 2 spec: resourceName: <sriov_resource_name> 3 nodeSelector: feature.node.kubernetes.io/network-sriov.capable: "true" 4 priority: <priority> 5 mtu: <mtu> 6 numVfs: <num> 7 nicSelector: 8 vendor: "<vendor_code>" 9 deviceID: "<device_id>" 10 pfNames: ["<pf_name>", ...] 11 rootDevices: ["<pci_bus_id>", "..."] 12 deviceType: vfio-pci 13 isRdma: false 14
- 1
- Specify a name for the CR object.
- 2
- Specify the namespace where the SR-IOV Operator is installed.
- 3
- Specify the resource name of the SR-IOV device plugin. You can create multiple
SriovNetworkNodePolicy
objects for a resource name. - 4
- Specify the node selector to select which nodes are configured. Only SR-IOV network devices on selected nodes are configured. The SR-IOV Container Network Interface (CNI) plugin and device plugin are deployed only on selected nodes.
- 5
- Optional: Specify an integer value between
0
and99
. A smaller number gets higher priority, so a priority of10
is higher than a priority of99
. The default value is99
. - 6
- Optional: Specify a value for the maximum transmission unit (MTU) of the virtual function. The maximum MTU value can vary for different NIC models.
- 7
- Specify the number of the virtual functions (VF) to create for the SR-IOV physical network device. For an Intel network interface controller (NIC), the number of VFs cannot be larger than the total VFs supported by the device. For a Mellanox NIC, the number of VFs cannot be larger than
127
. - 8
- The
nicSelector
mapping selects the Ethernet device for the Operator to configure. You do not need to specify values for all the parameters. It is recommended to identify the Ethernet adapter with enough precision to minimize the possibility of selecting an Ethernet device unintentionally. If you specifyrootDevices
, you must also specify a value forvendor
,deviceID
, orpfNames
. If you specify bothpfNames
androotDevices
at the same time, ensure that they point to an identical device. - 9
- Optional: Specify the vendor hex code of the SR-IOV network device. The only allowed values are either
8086
or15b3
. - 10
- Optional: Specify the device hex code of SR-IOV network device. The only allowed values are
158b
,1015
,1017
. - 11
- Optional: The parameter accepts an array of one or more physical function (PF) names for the Ethernet device.
- 12
- The parameter accepts an array of one or more PCI bus addresses for the physical function of the Ethernet device. Provide the address in the following format:
0000:02:00.1
. - 13
- The
vfio-pci
driver type is required for virtual functions in OpenShift Virtualization. - 14
- Optional: Specify whether to enable remote direct memory access (RDMA) mode. For a Mellanox card, set
isRdma
tofalse
. The default value isfalse
.
NoteIf
isRDMA
flag is set totrue
, you can continue to use the RDMA enabled VF as a normal network device. A device can be used in either mode.-
Optional: Label the SR-IOV capable cluster nodes with
SriovNetworkNodePolicy.Spec.NodeSelector
if they are not already labeled. For more information about labeling nodes, see "Understanding how to update labels on nodes". Create the
SriovNetworkNodePolicy
object:$ oc create -f <name>-sriov-node-network.yaml
where
<name>
specifies the name for this configuration.After applying the configuration update, all the pods in
sriov-network-operator
namespace transition to theRunning
status.To verify that the SR-IOV network device is configured, enter the following command. Replace
<node_name>
with the name of a node with the SR-IOV network device that you just configured.$ oc get sriovnetworknodestates -n openshift-sriov-network-operator <node_name> -o jsonpath='{.status.syncStatus}'
10.18.4.3. Configuring SR-IOV additional network
You can configure an additional network that uses SR-IOV hardware by creating an SriovNetwork
object.
When you create an SriovNetwork
object, the SR-IOV Network Operator automatically creates a NetworkAttachmentDefinition
object.
Do not modify or delete an SriovNetwork
object if it is attached to pods or virtual machines in a running
state.
Prerequisites
-
Install the OpenShift CLI (
oc
). -
Log in as a user with
cluster-admin
privileges.
Procedure
-
Create the following
SriovNetwork
object, and then save the YAML in the<name>-sriov-network.yaml
file. Replace<name>
with a name for this additional network.
apiVersion: sriovnetwork.openshift.io/v1 kind: SriovNetwork metadata: name: <name> 1 namespace: openshift-sriov-network-operator 2 spec: resourceName: <sriov_resource_name> 3 networkNamespace: <target_namespace> 4 vlan: <vlan> 5 spoofChk: "<spoof_check>" 6 linkState: <link_state> 7 maxTxRate: <max_tx_rate> 8 minTxRate: <min_rx_rate> 9 vlanQoS: <vlan_qos> 10 trust: "<trust_vf>" 11 capabilities: <capabilities> 12
- 1
- Replace
<name>
with a name for the object. The SR-IOV Network Operator creates aNetworkAttachmentDefinition
object with same name. - 2
- Specify the namespace where the SR-IOV Network Operator is installed.
- 3
- Replace
<sriov_resource_name>
with the value for the.spec.resourceName
parameter from theSriovNetworkNodePolicy
object that defines the SR-IOV hardware for this additional network. - 4
- Replace
<target_namespace>
with the target namespace for the SriovNetwork. Only pods or virtual machines in the target namespace can attach to the SriovNetwork. - 5
- Optional: Replace
<vlan>
with a Virtual LAN (VLAN) ID for the additional network. The integer value must be from0
to4095
. The default value is0
. - 6
- Optional: Replace
<spoof_check>
with the spoof check mode of the VF. The allowed values are the strings"on"
and"off"
.ImportantYou must enclose the value you specify in quotes or the CR is rejected by the SR-IOV Network Operator.
- 7
- Optional: Replace
<link_state>
with the link state of virtual function (VF). Allowed value areenable
,disable
andauto
. - 8
- Optional: Replace
<max_tx_rate>
with a maximum transmission rate, in Mbps, for the VF. - 9
- Optional: Replace
<min_tx_rate>
with a minimum transmission rate, in Mbps, for the VF. This value should always be less than or equal to Maximum transmission rate.NoteIntel NICs do not support the
minTxRate
parameter. For more information, see BZ#1772847. - 10
- Optional: Replace
<vlan_qos>
with an IEEE 802.1p priority level for the VF. The default value is0
. - 11
- Optional: Replace
<trust_vf>
with the trust mode of the VF. The allowed values are the strings"on"
and"off"
.ImportantYou must enclose the value you specify in quotes or the CR is rejected by the SR-IOV Network Operator.
- 12
- Optional: Replace
<capabilities>
with the capabilities to configure for this network.
To create the object, enter the following command. Replace
<name>
with a name for this additional network.$ oc create -f <name>-sriov-network.yaml
Optional: To confirm that the
NetworkAttachmentDefinition
object associated with theSriovNetwork
object that you created in the previous step exists, enter the following command. Replace<namespace>
with the namespace you specified in theSriovNetwork
object.$ oc get net-attach-def -n <namespace>
10.18.4.4. Connecting a virtual machine to an SR-IOV network
You can connect the virtual machine (VM) to the SR-IOV network by including the network details in the VM configuration.
Procedure
Include the SR-IOV network details in the
spec.domain.devices.interfaces
andspec.networks
of the VM configuration:kind: VirtualMachine # ... spec: domain: devices: interfaces: - name: <default> 1 masquerade: {} 2 - name: <nic1> 3 sriov: {} networks: - name: <default> 4 pod: {} - name: <nic1> 5 multus: networkName: <sriov-network> 6 # ...
- 1
- A unique name for the interface that is connected to the pod network.
- 2
- The
masquerade
binding to the default pod network. - 3
- A unique name for the SR-IOV interface.
- 4
- The name of the pod network interface. This must be the same as the
interfaces.name
that you defined earlier. - 5
- The name of the SR-IOV interface. This must be the same as the
interfaces.name
that you defined earlier. - 6
- The name of the SR-IOV network attachment definition.
Apply the virtual machine configuration:
$ oc apply -f <vm-sriov.yaml> 1
- 1
- The name of the virtual machine YAML file.
10.18.4.5. Configuring a cluster for DPDK workloads
You can use the following procedure to configure an OpenShift Container Platform cluster to run Data Plane Development Kit (DPDK) workloads.
Configuring a cluster for DPDK workloads is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.
Prerequisites
-
You have access to the cluster as a user with
cluster-admin
permissions. -
You have installed the OpenShift CLI (
oc
). - You have installed the SR-IOV Network Operator.
- You have installed the Node Tuning Operator.
Procedure
- Map your compute nodes topology to determine which Non-Uniform Memory Access (NUMA) CPUs are isolated for DPDK applications and which ones are reserved for the operating system (OS).
Label a subset of the compute nodes with a custom role; for example,
worker-dpdk
:$ oc label node <node_name> node-role.kubernetes.io/worker-dpdk=""
Create a new
MachineConfigPool
manifest that contains theworker-dpdk
label in thespec.machineConfigSelector
object:Example
MachineConfigPool
manifestapiVersion: machineconfiguration.openshift.io/v1 kind: MachineConfigPool metadata: name: worker-dpdk labels: machineconfiguration.openshift.io/role: worker-dpdk spec: machineConfigSelector: matchExpressions: - key: machineconfiguration.openshift.io/role operator: In values: - worker - worker-dpdk nodeSelector: matchLabels: node-role.kubernetes.io/worker-dpdk: ""
Create a
PerformanceProfile
manifest that applies to the labeled nodes and the machine config pool that you created in the previous steps. The performance profile specifies the CPUs that are isolated for DPDK applications and the CPUs that are reserved for house keeping.Example
PerformanceProfile
manifestapiVersion: performance.openshift.io/v2 kind: PerformanceProfile metadata: name: profile-1 spec: cpu: isolated: 4-39,44-79 reserved: 0-3,40-43 hugepages: defaultHugepagesSize: 1G pages: - count: 32 node: 0 size: 1G net: userLevelNetworking: true nodeSelector: node-role.kubernetes.io/worker-dpdk: "" numa: topologyPolicy: single-numa-node
NoteThe compute nodes automatically restart after you apply the
MachineConfigPool
andPerformanceProfile
manifests.Retrieve the name of the generated
RuntimeClass
resource from thestatus.runtimeClass
field of thePerformanceProfile
object:$ oc get performanceprofiles.performance.openshift.io profile-1 -o=jsonpath='{.status.runtimeClass}{"\n"}'
Set the previously obtained
RuntimeClass
name as the default container runtime class for thevirt-launcher
pods by adding the following annotation to theHyperConverged
custom resource (CR):$ oc annotate --overwrite -n openshift-cnv hco kubevirt-hyperconverged \ kubevirt.kubevirt.io/jsonpatch='[{"op": "add", "path": "/spec/configuration/defaultRuntimeClass", "value": <runtimeclass_name>}]'
NoteAdding the annotation to the
HyperConverged
CR changes a global setting that affects all VMs that are created after the annotation is applied. Setting this annotation breaches support of the OpenShift Virtualization instance and must be used only on test clusters. For best performance, apply for a support exception.Create an
SriovNetworkNodePolicy
object with thespec.deviceType
field set tovfio-pci
:Example
SriovNetworkNodePolicy
manifestapiVersion: sriovnetwork.openshift.io/v1 kind: SriovNetworkNodePolicy metadata: name: policy-1 namespace: openshift-sriov-network-operator spec: resourceName: intel_nics_dpdk deviceType: vfio-pci mtu: 9000 numVfs: 4 priority: 99 nicSelector: vendor: "8086" deviceID: "1572" pfNames: - eno3 rootDevices: - "0000:19:00.2" nodeSelector: feature.node.kubernetes.io/network-sriov.capable: "true"
10.18.4.6. Configuring a project for DPDK workloads
You can configure the project to run DPDK workloads on SR-IOV hardware.
Prerequisites
- Your cluster is configured to run DPDK workloads.
Procedure
Create a namespace for your DPDK applications:
$ oc create ns dpdk-checkup-ns
Create an
SriovNetwork
object that references theSriovNetworkNodePolicy
object. When you create anSriovNetwork
object, the SR-IOV Network Operator automatically creates aNetworkAttachmentDefinition
object.Example
SriovNetwork
manifestapiVersion: sriovnetwork.openshift.io/v1 kind: SriovNetwork metadata: name: dpdk-sriovnetwork namespace: openshift-sriov-network-operator spec: ipam: | { "type": "host-local", "subnet": "10.56.217.0/24", "rangeStart": "10.56.217.171", "rangeEnd": "10.56.217.181", "routes": [{ "dst": "0.0.0.0/0" }], "gateway": "10.56.217.1" } networkNamespace: dpdk-checkup-ns 1 resourceName: intel_nics_dpdk 2 spoofChk: "off" trust: "on" vlan: 1019
- Optional: Run the virtual machine latency checkup to verify that the network is properly configured.
- Optional: Run the DPDK checkup to verify that the namespace is ready for DPDK workloads.
Additional resources
10.18.4.7. Configuring a virtual machine for DPDK workloads
You can run Data Packet Development Kit (DPDK) workloads on virtual machines (VMs) to achieve lower latency and higher throughput for faster packet processing in the user space. DPDK uses the SR-IOV network for hardware-based I/O sharing.
Prerequisites
- Your cluster is configured to run DPDK workloads.
- You have created and configured the project in which the VM will run.
Procedure
Edit the
VirtualMachine
manifest to include information about the SR-IOV network interface, CPU topology, CRI-O annotations, and huge pages:Example
VirtualMachine
manifestapiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: name: rhel-dpdk-vm spec: running: true template: metadata: annotations: cpu-load-balancing.crio.io: disable 1 cpu-quota.crio.io: disable 2 irq-load-balancing.crio.io: disable 3 spec: domain: cpu: sockets: 1 4 cores: 5 5 threads: 2 dedicatedCpuPlacement: true isolateEmulatorThread: true interfaces: - masquerade: {} name: default - model: virtio name: nic-east pciAddress: '0000:07:00.0' sriov: {} networkInterfaceMultiqueue: true rng: {} memory: hugepages: pageSize: 1Gi 6 guest: 8Gi networks: - name: default pod: {} - multus: networkName: dpdk-net 7 name: nic-east # ...
- 1
- This annotation specifies that load balancing is disabled for CPUs that are used by the container.
- 2
- This annotation specifies that the CPU quota is disabled for CPUs that are used by the container.
- 3
- This annotation specifies that Interrupt Request (IRQ) load balancing is disabled for CPUs that are used by the container.
- 4
- The number of sockets inside the VM. This field must be set to
1
for the CPUs to be scheduled from the same Non-Uniform Memory Access (NUMA) node. - 5
- The number of cores inside the VM. This must be a value greater than or equal to
1
. In this example, the VM is scheduled with 5 hyper-threads or 10 CPUs. - 6
- The size of the huge pages. The possible values for x86-64 architecture are 1Gi and 2Mi. In this example, the request is for 8 huge pages of size 1Gi.
- 7
- The name of the SR-IOV
NetworkAttachmentDefinition
object.
- Save and exit the editor.
Apply the
VirtualMachine
manifest:$ oc apply -f <file_name>.yaml
Configure the guest operating system. The following example shows the configuration steps for RHEL 8 OS:
Configure huge pages by using the GRUB bootloader command-line interface. In the following example, 8 1G huge pages are specified.
$ grubby --update-kernel=ALL --args="default_hugepagesz=1GB hugepagesz=1G hugepages=8"
To achieve low-latency tuning by using the
cpu-partitioning
profile in the TuneD application, run the following commands:$ dnf install -y tuned-profiles-cpu-partitioning
$ echo isolated_cores=2-9 > /etc/tuned/cpu-partitioning-variables.conf
The first two CPUs (0 and 1) are set aside for house keeping tasks and the rest are isolated for the DPDK application.
$ tuned-adm profile cpu-partitioning
Override the SR-IOV NIC driver by using the
driverctl
device driver control utility:$ dnf install -y driverctl
$ driverctl set-override 0000:07:00.0 vfio-pci
- Restart the VM to apply the changes.
10.18.4.8. Next steps
10.18.5. Connecting a virtual machine to a service mesh
OpenShift Virtualization is now integrated with OpenShift Service Mesh. You can monitor, visualize, and control traffic between pods that run virtual machine workloads on the default pod network with IPv4.
10.18.5.1. Prerequisites
- You must have installed the Service Mesh Operator and deployed the service mesh control plane.
- You must have added the namespace where the virtual machine is created to the service mesh member roll.
-
You must use the
masquerade
binding method for the default pod network.
10.18.5.2. Configuring a virtual machine for the service mesh
To add a virtual machine (VM) workload to a service mesh, enable automatic sidecar injection in the VM configuration file by setting the sidecar.istio.io/inject
annotation to true
. Then expose your VM as a service to view your application in the mesh.
Prerequisites
- To avoid port conflicts, do not use ports used by the Istio sidecar proxy. These include ports 15000, 15001, 15006, 15008, 15020, 15021, and 15090.
Procedure
Edit the VM configuration file to add the
sidecar.istio.io/inject: "true"
annotation.Example configuration file
apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: labels: kubevirt.io/vm: vm-istio name: vm-istio spec: runStrategy: Always template: metadata: labels: kubevirt.io/vm: vm-istio app: vm-istio 1 annotations: sidecar.istio.io/inject: "true" 2 spec: domain: devices: interfaces: - name: default masquerade: {} 3 disks: - disk: bus: virtio name: containerdisk - disk: bus: virtio name: cloudinitdisk resources: requests: memory: 1024M networks: - name: default pod: {} terminationGracePeriodSeconds: 180 volumes: - containerDisk: image: registry:5000/kubevirt/fedora-cloud-container-disk-demo:devel name: containerdisk
Apply the VM configuration:
$ oc apply -f <vm_name>.yaml 1
- 1
- The name of the virtual machine YAML file.
Create a
Service
object to expose your VM to the service mesh.apiVersion: v1 kind: Service metadata: name: vm-istio spec: selector: app: vm-istio 1 ports: - port: 8080 name: http protocol: TCP
- 1
- The service selector that determines the set of pods targeted by a service. This attribute corresponds to the
spec.metadata.labels
field in the VM configuration file. In the above example, theService
object namedvm-istio
targets TCP port 8080 on any pod with the labelapp=vm-istio
.
Create the service:
$ oc create -f <service_name>.yaml 1
- 1
- The name of the service YAML file.
10.18.6. Configuring IP addresses for virtual machines
You can configure static and dynamic IP addresses for virtual machines.
10.18.6.1. Configuring an IP address for a new virtual machine using cloud-init
You can use cloud-init to configure the IP address of a secondary NIC when you create a virtual machine (VM). The IP address can be dynamically or statically provisioned.
If the VM is connected to the pod network, the pod network interface is the default route unless you update it.
Prerequisites
- The virtual machine is connected to a secondary network.
- You have a DHCP server available on the secondary network to configure a dynamic IP for the virtual machine.
Procedure
Edit the
spec.template.spec.volumes.cloudInitNoCloud.networkData
stanza of the virtual machine configuration:To configure a dynamic IP address, specify the interface name and enable DHCP:
kind: VirtualMachine spec: # ... template: # ... spec: volumes: - cloudInitNoCloud: networkData: | version: 2 ethernets: eth1: 1 dhcp4: true
- 1
- Specify the interface name.
To configure a static IP, specify the interface name and the IP address:
kind: VirtualMachine spec: # ... template: # ... spec: volumes: - cloudInitNoCloud: networkData: | version: 2 ethernets: eth1: 1 addresses: - 10.10.10.14/24 2
10.18.7. Viewing the IP address of NICs on a virtual machine
You can view the IP address for a network interface controller (NIC) by using the web console or the oc
client. The QEMU guest agent displays additional information about the virtual machine’s secondary networks.
10.18.7.1. Prerequisites
- Install the QEMU guest agent on the virtual machine.
10.18.7.2. Viewing the IP address of a virtual machine interface in the CLI
The network interface configuration is included in the oc describe vmi <vmi_name>
command.
You can also view the IP address information by running ip addr
on the virtual machine, or by running oc get vmi <vmi_name> -o yaml
.
Procedure
Use the
oc describe
command to display the virtual machine interface configuration:$ oc describe vmi <vmi_name>
Example output
# ... Interfaces: Interface Name: eth0 Ip Address: 10.244.0.37/24 Ip Addresses: 10.244.0.37/24 fe80::858:aff:fef4:25/64 Mac: 0a:58:0a:f4:00:25 Name: default Interface Name: v2 Ip Address: 1.1.1.7/24 Ip Addresses: 1.1.1.7/24 fe80::f4d9:70ff:fe13:9089/64 Mac: f6:d9:70:13:90:89 Interface Name: v1 Ip Address: 1.1.1.1/24 Ip Addresses: 1.1.1.1/24 1.1.1.2/24 1.1.1.4/24 2001:de7:0:f101::1/64 2001:db8:0:f101::1/64 fe80::1420:84ff:fe10:17aa/64 Mac: 16:20:84:10:17:aa
10.18.7.3. Viewing the IP address of a virtual machine interface in the web console
The IP information is displayed on the VirtualMachine details page for the virtual machine.
Procedure
-
In the OpenShift Container Platform console, click Virtualization
VirtualMachines from the side menu. - Select a virtual machine name to open the VirtualMachine details page.
The information for each attached NIC is displayed under IP Address on the Details tab.
10.18.8. Accessing a virtual machine on a secondary network by using the cluster domain name
You can access a virtual machine (VM) that is attached to a secondary network interface from outside the cluster by using the fully qualified domain name (FQDN) of the cluster.
Accessing VMs by using the cluster FQDN is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.
10.18.8.1. Configuring DNS server for secondary networks
The Cluster Network Addons Operator (CNAO) deploys the Domain Name Server (DNS) server and monitoring components when you enable the KubeSecondaryDNS
feature gate in the HyperConverged
custom resource (CR).
Prerequisites
-
You installed the OpenShift CLI (
oc
). -
You have access to an OpenShift Container Platform cluster with
cluster-admin
permissions.
Procedure
Create a
LoadBalancer
service using MetalLB or any other load balancer to expose the DNS server outside the cluster. The service listens on port 53 and targets port 5353. For example:$ oc expose -n openshift-cnv deployment/secondary-dns --name=dns-lb --type=LoadBalancer --port=53 --target-port=5353 --protocol='UDP'
Retrieve the public IP address of the service by querying the
Service
object:$ oc get service -n openshift-cnv
Example output
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE dns-lb LoadBalancer 172.30.27.5 10.46.41.94 53:31829/TCP 5s
Deploy the DNS server and monitoring components by editing the
HyperConverged
CR:apiVersion: hco.kubevirt.io/v1beta1 kind: HyperConverged metadata: name: kubevirt-hyperconverged namespace: openshift-cnv spec: featureGates: deployKubeSecondaryDNS: true 1 kubeSecondaryDNSNameServerIP: "10.46.41.94" 2 # ...
Retrieve the FQDN of the OpenShift Container Platform cluster by using the following command:
$ oc get dnses.config.openshift.io cluster -o json | jq .spec.baseDomain
Example output
openshift.example.com
Point to the DNS server by using one of the following methods:
Add the
kubeSecondaryDNSNameServerIP
value to theresolv.conf
file on your local machine.NoteEditing the
resolv.conf
file overwrites any existing DNS settings.Add the
kubeSecondaryDNSNameServerIP
value and the cluster FQDN to the enterprise DNS server records. For example:vm.<FQDN>. IN NS ns.vm.<FQDN>.
ns.vm.<FQDN>. IN A 10.46.41.94
10.18.8.2. Connecting to a virtual machine on a secondary network by using the cluster FQDN
You can access a virtual machine (VM) that is attached to a secondary network interface from outside the cluster by using the fully qualified domain name (FQDN) of the cluster.
Prerequisites
- The QEMU guest agent must be running on the virtual machine.
- The IP address of the VM that you want to connect to, by using a DNS client, must be public.
- You have configured the DNS server for secondary networks.
- You have retrieved the fully qualified domain name (FQDN) of the cluster.
Procedure
Retrieve the VM configuration by using the following command:
$ oc get vm -n <namespace> <vm_name> -o yaml
Example output
apiVersion: kubevirt.io/v1 kind: VirtualMachine metadata: labels: kubevirt.io/vm: example-vm name: example-vm namespace: example-namespace spec: running: true template: metadata: labels: kubevirt.io/vm: example-vm spec: domain: devices: # ... interfaces: - bridge: {} name: example-nic # ... networks: - multus: networkName: bridge-conf name: example-nic 1 # ...
- 1
- Specify the name of the secondary network interface.
Connect to the VM by using the
ssh
command:$ ssh <user_name>@<interface_name>.<vm_name>.<namespace>.vm.<FQDN> 1
- 1
- Specify the user name, interface name, VM name, VM namespace, and FQDN.
Example
$ ssh you@example-nic.example-vm.example-namespace.vm.openshift.example.com
10.18.8.3. Additional resources
10.18.9. Using a MAC address pool for virtual machines
The KubeMacPool component provides a MAC address pool service for virtual machine NICs in a namespace.
10.18.9.1. About KubeMacPool
KubeMacPool provides a MAC address pool per namespace and allocates MAC addresses for virtual machine NICs from the pool. This ensures that the NIC is assigned a unique MAC address that does not conflict with the MAC address of another virtual machine.
Virtual machine instances created from that virtual machine retain the assigned MAC address across reboots.
KubeMacPool does not handle virtual machine instances created independently from a virtual machine.
KubeMacPool is enabled by default when you install OpenShift Virtualization. You can disable a MAC address pool for a namespace by adding the mutatevirtualmachines.kubemacpool.io=ignore
label to the namespace. Re-enable KubeMacPool for the namespace by removing the label.
10.18.9.2. Disabling a MAC address pool for a namespace in the CLI
Disable a MAC address pool for virtual machines in a namespace by adding the mutatevirtualmachines.kubemacpool.io=ignore
label to the namespace.
Procedure
Add the
mutatevirtualmachines.kubemacpool.io=ignore
label to the namespace. The following example disables KubeMacPool for two namespaces,<namespace1>
and<namespace2>
:$ oc label namespace <namespace1> <namespace2> mutatevirtualmachines.kubemacpool.io=ignore
10.18.9.3. Re-enabling a MAC address pool for a namespace in the CLI
If you disabled KubeMacPool for a namespace and want to re-enable it, remove the mutatevirtualmachines.kubemacpool.io=ignore
label from the namespace.
Earlier versions of OpenShift Virtualization used the label mutatevirtualmachines.kubemacpool.io=allocate
to enable KubeMacPool for a namespace. This is still supported but redundant as KubeMacPool is now enabled by default.
Procedure
Remove the KubeMacPool label from the namespace. The following example re-enables KubeMacPool for two namespaces,
<namespace1>
and<namespace2>
:$ oc label namespace <namespace1> <namespace2> mutatevirtualmachines.kubemacpool.io-
10.19. Virtual machine disks
10.19.1. Configuring local storage for virtual machines
You can configure local storage for virtual machines by using the hostpath provisioner (HPP).
When you install the OpenShift Virtualization Operator, the Hostpath Provisioner (HPP) Operator is automatically installed. The HPP is a local storage provisioner designed for OpenShift Virtualization that is created by the Hostpath Provisioner Operator. To use the HPP, you must create an HPP custom resource (CR).
10.19.1.1. Creating a hostpath provisioner with a basic storage pool
You configure a hostpath provisioner (HPP) with a basic storage pool by creating an HPP custom resource (CR) with a storagePools
stanza. The storage pool specifies the name and path used by the CSI driver.
Prerequisites
-
The directories specified in
spec.storagePools.path
must have read/write access. - The storage pools must not be in the same partition as the operating system. Otherwise, the operating system partition might become filled to capacity, which will impact performance or cause the node to become unstable or unusable.
Procedure
Create an
hpp_cr.yaml
file with astoragePools
stanza as in the following example:apiVersion: hostpathprovisioner.kubevirt.io/v1beta1 kind: HostPathProvisioner metadata: name: hostpath-provisioner spec: imagePullPolicy: IfNotPresent storagePools: 1 - name: any_name path: "/var/myvolumes" 2 workload: nodeSelector: kubernetes.io/os: linux
- Save the file and exit.
Create the HPP by running the following command:
$ oc create -f hpp_cr.yaml
10.19.1.1.1. About creating storage classes
When you create a storage class, you set parameters that affect the dynamic provisioning of persistent volumes (PVs) that belong to that storage class. You cannot update a StorageClass
object’s parameters after you create it.
In order to use the hostpath provisioner (HPP) you must create an associated storage class for the CSI driver with the storagePools
stanza.
Virtual machines use data volumes that are based on local PVs. Local PVs are bound to specific nodes. While the disk image is prepared for consumption by the virtual machine, it is possible that the virtual machine cannot be scheduled to the node where the local storage PV was previously pinned.
To solve this problem, use the Kubernetes pod scheduler to bind the persistent volume claim (PVC) to a PV on the correct node. By using the StorageClass
value with volumeBindingMode
parameter set to WaitForFirstConsumer
, the binding and provisioning of the PV is delayed until a pod is created using the PVC.
10.19.1.1.2. Creating a storage class for the CSI driver with the storagePools stanza
You create a storage class custom resource (CR) for the hostpath provisioner (HPP) CSI driver.
Procedure
Create a
storageclass_csi.yaml
file to define the storage class:apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: hostpath-csi provisioner: kubevirt.io.hostpath-provisioner reclaimPolicy: Delete 1 volumeBindingMode: WaitForFirstConsumer 2 parameters: storagePool: my-storage-pool 3
- 1
- The two possible
reclaimPolicy
values areDelete
andRetain
. If you do not specify a value, the default value isDelete
. - 2
- The
volumeBindingMode
parameter determines when dynamic provisioning and volume binding occur. SpecifyWaitForFirstConsumer
to delay the binding and provisioning of a persistent volume (PV) until after a pod that uses the persistent volume claim (PVC) is created. This ensures that the PV meets the pod’s scheduling requirements. - 3
- Specify the name of the storage pool defined in the HPP CR.
- Save the file and exit.
Create the
StorageClass
object by running the following command:$ oc create -f storageclass_csi.yaml
10.19.1.2. About storage pools created with PVC templates
If you have a single, large persistent volume (PV), you can create a storage pool by defining a PVC template in the hostpath provisioner (HPP) custom resource (CR).
A storage pool created with a PVC template can contain multiple HPP volumes. Splitting a PV into smaller volumes provides greater flexibility for data allocation.
The PVC template is based on the spec
stanza of the PersistentVolumeClaim
object:
Example PersistentVolumeClaim
object
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: iso-pvc
spec:
volumeMode: Block 1
storageClassName: my-storage-class
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 5Gi
- 1
- This value is only required for block volume mode PVs.
You define a storage pool using a pvcTemplate
specification in the HPP CR. The Operator creates a PVC from the pvcTemplate
specification for each node containing the HPP CSI driver. The PVC created from the PVC template consumes the single large PV, allowing the HPP to create smaller dynamic volumes.
You can combine basic storage pools with storage pools created from PVC templates.
10.19.1.2.1. Creating a storage pool with a PVC template
You can create a storage pool for multiple hostpath provisioner (HPP) volumes by specifying a PVC template in the HPP custom resource (CR).
Prerequisites
-
The directories specified in
spec.storagePools.path
must have read/write access. - The storage pools must not be in the same partition as the operating system. Otherwise, the operating system partition might become filled to capacity, which will impact performance or cause the node to become unstable or unusable.
Procedure
Create an
hpp_pvc_template_pool.yaml
file for the HPP CR that specifies a persistent volume (PVC) template in thestoragePools
stanza according to the following example:apiVersion: hostpathprovisioner.kubevirt.io/v1beta1 kind: HostPathProvisioner metadata: name: hostpath-provisioner spec: imagePullPolicy: IfNotPresent storagePools: 1 - name: my-storage-pool path: "/var/myvolumes" 2 pvcTemplate: volumeMode: Block 3 storageClassName: my-storage-class 4 accessModes: - ReadWriteOnce resources: requests: storage: 5Gi 5 workload: nodeSelector: kubernetes.io/os: linux
- 1
- The
storagePools
stanza is an array that can contain both basic and PVC template storage pools. - 2
- Specify the storage pool directories under this node path.
- 3
- Optional: The
volumeMode
parameter can be eitherBlock
orFilesystem
as long as it matches the provisioned volume format. If no value is specified, the default isFilesystem
. If thevolumeMode
isBlock
, the mounting pod creates an XFS file system on the block volume before mounting it. - 4
- If the
storageClassName
parameter is omitted, the default storage class is used to create PVCs. If you omitstorageClassName
, ensure that the HPP storage class is not the default storage class. - 5
- You can specify statically or dynamically provisioned storage. In either case, ensure the requested storage size is appropriate for the volume you want to virtually divide or the PVC cannot be bound to the large PV. If the storage class you are using uses dynamically provisioned storage, pick an allocation size that matches the size of a typical request.
- Save the file and exit.
Create the HPP with a storage pool by running the following command:
$ oc create -f hpp_pvc_template_pool.yaml
Additional resources
10.19.2. Creating data volumes
You can create a data volume by using either the PVC or storage API.
When using OpenShift Virtualization with OpenShift Container Platform Container Storage, specify RBD block mode persistent volume claims (PVCs) when creating virtual machine disks. With virtual machine disks, RBD block mode volumes are more efficient and provide better performance than Ceph FS or RBD filesystem-mode PVCs.
To specify RBD block mode PVCs, use the 'ocs-storagecluster-ceph-rbd' storage class and VolumeMode: Block
.
Whenever possible, use the storage API to optimize space allocation and maximize performance.
A storage profile is a custom resource that the CDI manages. It provides recommended storage settings based on the associated storage class. A storage profile is allocated for each storage class.
Storage profiles enable you to create data volumes quickly while reducing coding and minimizing potential errors.
For recognized storage types, the CDI provides values that optimize the creation of PVCs. However, you can configure automatic settings for a storage class if you customize the storage profile.
10.19.2.1. About data volumes
DataVolume
objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). You can create a data volume as either a standalone resource or by using the dataVolumeTemplate
field in the virtual machine (VM) specification.
-
VM disk PVCs that are prepared by using standalone data volumes maintain an independent lifecycle from the VM. If you use the
dataVolumeTemplate
field in the VM specification to prepare the PVC, the PVC shares the same lifecycle as the VM.
10.19.2.2. Creating data volumes using the storage API
When you create a data volume using the storage API, the Containerized Data Interface (CDI) optimizes your persistent volume claim (PVC) allocation based on the type of storage supported by your selected storage class. You only have to specify the data volume name, namespace, and the amount of storage that you want to allocate.
For example:
-
When using Ceph RBD,
accessModes
is automatically set toReadWriteMany
, which enables live migration.volumeMode
is set toBlock
to maximize performance. -
When you are using
volumeMode: Filesystem
, more space will automatically be requested by the CDI, if required to accommodate file system overhead.
In the following YAML, using the storage API requests a data volume with two gigabytes of usable space. The user does not need to know the volumeMode
in order to correctly estimate the required persistent volume claim (PVC) size. The CDI chooses the optimal combination of accessModes
and volumeMode
attributes automatically. These optimal values are based on the type of storage or the defaults that you define in your storage profile. If you want to provide custom values, they override the system-calculated values.
Example DataVolume definition
apiVersion: cdi.kubevirt.io/v1beta1 kind: DataVolume metadata: name: <datavolume> 1 spec: source: pvc: 2 namespace: "<source_namespace>" 3 name: "<my_vm_disk>" 4 storage: 5 resources: requests: storage: 2Gi 6 storageClassName: <storage_class> 7
- 1
- The name of the new data volume.
- 2
- Indicate that the source of the import is an existing persistent volume claim (PVC).
- 3
- The namespace where the source PVC exists.
- 4
- The name of the source PVC.
- 5
- Indicates allocation using the storage API.
- 6
- Specifies the amount of available space that you request for the PVC.
- 7
- Optional: The name of the storage class. If the storage class is not specified, the system default storage class is used.
10.19.2.3. Creating data volumes using the PVC API
When you create a data volume using the PVC API, the Containerized Data Interface (CDI) creates the data volume based on what you specify for the following fields:
-
accessModes
(ReadWriteOnce
,ReadWriteMany
, orReadOnlyMany
) -
volumeMode
(Filesystem
orBlock
) -
capacity
ofstorage
(5Gi
, for example)
In the following YAML, using the PVC API allocates a data volume with a storage capacity of two gigabytes. You specify an access mode of ReadWriteMany
to enable live migration. Because you know the values your system can support, you specify Block
storage instead of the default, Filesystem
.
Example DataVolume definition
apiVersion: cdi.kubevirt.io/v1beta1 kind: DataVolume metadata: name: <datavolume> 1 spec: source: pvc: 2 namespace: "<source_namespace>" 3 name: "<my_vm_disk>" 4 pvc: 5 accessModes: 6 - ReadWriteMany resources: requests: storage: 2Gi 7 volumeMode: Block 8 storageClassName: <storage_class> 9
- 1
- The name of the new data volume.
- 2
- In the
source
section,pvc
indicates that the source of the import is an existing persistent volume claim (PVC). - 3
- The namespace where the source PVC exists.
- 4
- The name of the source PVC.
- 5
- Indicates allocation using the PVC API.
- 6
accessModes
is required when using the PVC API.- 7
- Specifies the amount of space you are requesting for your data volume.
- 8
- Specifies that the destination is a block PVC.
- 9
- Optionally, specify the storage class. If the storage class is not specified, the system default storage class is used.
When you explicitly allocate a data volume by using the PVC API and you are not using volumeMode: Block
, consider file system overhead.
File system overhead is the amount of space required by the file system to maintain its metadata. The amount of space required for file system metadata is file system dependent. Failing to account for file system overhead in your storage capacity request can result in an underlying persistent volume claim (PVC) that is not large enough to accommodate your virtual machine disk.
If you use the storage API, the CDI will factor in file system overhead and request a larger persistent volume claim (PVC) to ensure that your allocation request is successful.
10.19.2.4. Customizing the storage profile
You can specify default parameters by editing the StorageProfile
object for the provisioner’s storage class. These default parameters only apply to the persistent volume claim (PVC) if they are not configured in the DataVolume
object.
An empty status
section in a storage profile indicates that a storage provisioner is not recognized by the Containerized Data Interface (CDI). Customizing a storage profile is necessary if you have a storage provisioner that is not recognized by the CDI. In this case, the administrator sets appropriate values in the storage profile to ensure successful allocations.
If you create a data volume and omit YAML attributes and these attributes are not defined in the storage profile, then the requested storage will not be allocated and the underlying persistent volume claim (PVC) will not be created.
Prerequisites
- Ensure that your planned configuration is supported by the storage class and its provider. Specifying an incompatible configuration in a storage profile causes volume provisioning to fail.
Procedure
Edit the storage profile. In this example, the provisioner is not recognized by CDI:
$ oc edit -n openshift-cnv storageprofile <storage_class>
Example storage profile
apiVersion: cdi.kubevirt.io/v1beta1 kind: StorageProfile metadata: name: <unknown_provisioner_class> # ... spec: {} status: provisioner: <unknown_provisioner> storageClass: <unknown_provisioner_class>
Provide the needed attribute values in the storage profile:
Example storage profile
apiVersion: cdi.kubevirt.io/v1beta1 kind: StorageProfile metadata: name: <unknown_provisioner_class> # ... spec: claimPropertySets: - accessModes: - ReadWriteOnce 1 volumeMode: Filesystem 2 status: provisioner: <unknown_provisioner> storageClass: <unknown_provisioner_class>
After you save your changes, the selected values appear in the storage profile
status
element.
10.19.2.4.1. Setting a default cloning strategy using a storage profile
You can use storage profiles to set a default cloning method for a storage class, creating a cloning strategy. Setting cloning strategies can be helpful, for example, if your storage vendor only supports certain cloning methods. It also allows you to select a method that limits resource usage or maximizes performance.
Cloning strategies can be specified by setting the cloneStrategy
attribute in a storage profile to one of these values:
-
snapshot
is used by default when snapshots are configured. This cloning strategy uses a temporary volume snapshot to clone the volume. The storage provisioner must support Container Storage Interface (CSI) snapshots. -
copy
uses a source pod and a target pod to copy data from the source volume to the target volume. Host-assisted cloning is the least efficient method of cloning. -
csi-clone
uses the CSI clone API to efficiently clone an existing volume without using an interim volume snapshot. Unlikesnapshot
orcopy
, which are used by default if no storage profile is defined, CSI volume cloning is only used when you specify it in theStorageProfile
object for the provisioner’s storage class.
You can also set clone strategies using the CLI without modifying the default claimPropertySets
in your YAML spec
section.
Example storage profile
apiVersion: cdi.kubevirt.io/v1beta1 kind: StorageProfile metadata: name: <provisioner_class> # ... spec: claimPropertySets: - accessModes: - ReadWriteOnce 1 volumeMode: Filesystem 2 cloneStrategy: csi-clone 3 status: provisioner: <provisioner> storageClass: <provisioner_class>
10.19.2.5. Additional resources
10.19.3. Reserving PVC space for file system overhead
By default, the OpenShift Virtualization reserves space for file system overhead data in persistent volume claims (PVCs) that use the Filesystem
volume mode. You can set the percentage to reserve space for this purpose globally and for specific storage classes.
10.19.3.1. How file system overhead affects space for virtual machine disks
When you add a virtual machine disk to a persistent volume claim (PVC) that uses the Filesystem
volume mode, you must ensure that there is enough space on the PVC for:
- The virtual machine disk.
- The space reserved for file system overhead, such as metadata
By default, OpenShift Virtualization reserves 5.5% of the PVC space for overhead, reducing the space available for virtual machine disks by that amount.
You can configure a different overhead value by editing the HCO
object. You can change the value globally and you can specify values for specific storage classes.
10.19.3.2. Overriding the default file system overhead value
Change the amount of persistent volume claim (PVC) space that the OpenShift Virtualization reserves for file system overhead by editing the spec.filesystemOverhead
attribute of the HCO
object.
Prerequisites
-
Install the OpenShift CLI (
oc
).
Procedure
Open the
HCO
object for editing by running the following command:$ oc edit hco -n openshift-cnv kubevirt-hyperconverged
Edit the
spec.filesystemOverhead
fields, populating them with your chosen values:# ... spec: filesystemOverhead: global: "<new_global_value>" 1 storageClass: <storage_class_name>: "<new_value_for_this_storage_class>" 2
- 1
- The default file system overhead percentage used for any storage classes that do not already have a set value. For example,
global: "0.07"
reserves 7% of the PVC for file system overhead. - 2
- The file system overhead percentage for the specified storage class. For example,
mystorageclass: "0.04"
changes the default overhead value for PVCs in themystorageclass
storage class to 4%.
-
Save and exit the editor to update the
HCO
object.
Verification
View the
CDIConfig
status and verify your changes by running one of the following commands:To generally verify changes to
CDIConfig
:$ oc get cdiconfig -o yaml
To view your specific changes to
CDIConfig
:$ oc get cdiconfig -o jsonpath='{.items..status.filesystemOverhead}'
10.19.4. Configuring CDI to work with namespaces that have a compute resource quota
You can use the Containerized Data Importer (CDI) to import, upload, and clone virtual machine disks into namespaces that are subject to CPU and memory resource restrictions.
10.19.4.1. About CPU and memory quotas in a namespace
A resource quota, defined by the ResourceQuota
object, imposes restrictions on a namespace that limit the total amount of compute resources that can be consumed by resources within that namespace.
The HyperConverged
custom resource (CR) defines the user configuration for the Containerized Data Importer (CDI). The CPU and memory request and limit values are set to a default value of 0
. This ensures that pods created by CDI that do not specify compute resource requirements are given the default values and are allowed to run in a namespace that is restricted with a quota.
10.19.4.2. Overriding CPU and memory defaults
Modify the default settings for CPU and memory requests and limits for your use case by adding the spec.resourceRequirements.storageWorkloads
stanza to the HyperConverged
custom resource (CR).
Prerequisites
-
Install the OpenShift CLI (
oc
).
Procedure
Edit the
HyperConverged
CR by running the following command:$ oc edit hco -n openshift-cnv kubevirt-hyperconverged
Add the
spec.resourceRequirements.storageWorkloads
stanza to the CR, setting the values based on your use case. For example:apiVersion: hco.kubevirt.io/v1beta1 kind: HyperConverged metadata: name: kubevirt-hyperconverged spec: resourceRequirements: storageWorkloads: limits: cpu: "500m" memory: "2Gi" requests: cpu: "250m" memory: "1Gi"
-
Save and exit the editor to update the
HyperConverged
CR.
10.19.4.3. Additional resources
10.19.5. Managing data volume annotations
Data volume (DV) annotations allow you to manage pod behavior. You can add one or more annotations to a data volume, which then propagates to the created importer pods.
10.19.5.1. Example: Data volume annotations
This example shows how you can configure data volume (DV) annotations to control which network the importer pod uses. The v1.multus-cni.io/default-network: bridge-network
annotation causes the pod to use the multus network named bridge-network
as its default network. If you want the importer pod to use both the default network from the cluster and the secondary multus network, use the k8s.v1.cni.cncf.io/networks: <network_name>
annotation.
Multus network annotation example
apiVersion: cdi.kubevirt.io/v1beta1
kind: DataVolume
metadata:
name: dv-ann
annotations:
v1.multus-cni.io/default-network: bridge-network 1
spec:
source:
http:
url: "example.exampleurl.com"
pvc:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
- 1
- Multus network annotation
10.19.6. Using preallocation for data volumes
The Containerized Data Importer can preallocate disk space to improve write performance when creating data volumes.
You can enable preallocation for specific data volumes.
10.19.6.1. About preallocation
The Containerized Data Importer (CDI) can use the QEMU preallocate mode for data volumes to improve write performance. You can use preallocation mode for importing and uploading operations and when creating blank data volumes.
If preallocation is enabled, CDI uses the better preallocation method depending on the underlying file system and device type:
fallocate
-
If the file system supports it, CDI uses the operating system’s
fallocate
call to preallocate space by using theposix_fallocate
function, which allocates blocks and marks them as uninitialized. full
-
If
fallocate
mode cannot be used,full
mode allocates space for the image by writing data to the underlying storage. Depending on the storage location, all the empty allocated space might be zeroed.
10.19.6.2. Enabling preallocation for a data volume
You can enable preallocation for specific data volumes by including the spec.preallocation
field in the data volume manifest. You can enable preallocation mode in either the web console or by using the OpenShift CLI (oc
).
Preallocation mode is supported for all CDI source types.
Procedure
Specify the
spec.preallocation
field in the data volume manifest:apiVersion: cdi.kubevirt.io/v1beta1 kind: DataVolume metadata: name: preallocated-datavolume spec: source: 1 ... pvc: ... preallocation: true 2
10.19.7. Uploading local disk images by using the web console
You can upload a locally stored disk image file by using the web console.
10.19.7.1. Prerequisites
- You must have a virtual machine image file in IMG, ISO, or QCOW2 format.
- If you require scratch space according to the CDI supported operations matrix, you must first define a storage class or prepare CDI scratch space for this operation to complete successfully.
10.19.7.2. CDI supported operations matrix
This matrix shows the supported CDI operations for content types against endpoints, and which of these operations requires scratch space.
Content types | HTTP | HTTPS | HTTP basic auth | Registry | Upload |
---|---|---|---|---|---|
KubeVirt (QCOW2) |
✓ QCOW2 |
✓ QCOW2** |
✓ QCOW2 |
✓ QCOW2* |
✓ QCOW2* |
KubeVirt (RAW) |
✓ RAW |
✓ RAW |
✓ RAW |
✓ RAW* |
✓ RAW* |
✓ Supported operation
□ Unsupported operation
* Requires scratch space
** Requires scratch space if a custom certificate authority is required
10.19.7.3. Uploading an image file using the web console
Use the web console to upload an image file to a new persistent volume claim (PVC). You can later use this PVC to attach the image to new virtual machines.
Prerequisites
You must have one of the following:
- A raw virtual machine image file in either ISO or IMG format.
- A virtual machine image file in QCOW2 format.
For best results, compress your image file according to the following guidelines before you upload it:
Compress a raw image file by using
xz
orgzip
.NoteUsing a compressed raw image file results in the most efficient upload.
Compress a QCOW2 image file by using the method that is recommended for your client:
- If you use a Linux client, sparsify the QCOW2 file by using the virt-sparsify tool.
-
If you use a Windows client, compress the QCOW2 file by using
xz
orgzip
.
Procedure
-
From the side menu of the web console, click Storage
Persistent Volume Claims. - Click the Create Persistent Volume Claim drop-down list to expand it.
- Click With Data Upload Form to open the Upload Data to Persistent Volume Claim page.
- Click Browse to open the file manager and select the image that you want to upload, or drag the file into the Drag a file here or browse to upload field.
Optional: Set this image as the default image for a specific operating system.
- Select the Attach this data to a virtual machine operating system check box.
- Select an operating system from the list.
- The Persistent Volume Claim Name field is automatically filled with a unique name and cannot be edited. Take note of the name assigned to the PVC so that you can identify it later, if necessary.
- Select a storage class from the Storage Class list.
In the Size field, enter the size value for the PVC. Select the corresponding unit of measurement from the drop-down list.
WarningThe PVC size must be larger than the size of the uncompressed virtual disk.
- Select an Access Mode that matches the storage class that you selected.
- Click Upload.
10.19.7.4. Additional resources
- Configure preallocation mode to improve write performance for data volume operations.
10.19.8. Uploading local disk images by using the virtctl tool
You can upload a locally stored disk image to a new or existing persistent volume claim (PVC) by using the virtctl
command-line utility.
10.19.8.1. Prerequisites
-
Install
virtctl
. - You might need to define a storage class or prepare CDI scratch space for this operation to complete successfully.
10.19.8.2. About data volumes
DataVolume
objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). You can create a data volume as either a standalone resource or by using the dataVolumeTemplate
field in the virtual machine (VM) specification.
-
VM disk PVCs that are prepared by using standalone data volumes maintain an independent lifecycle from the VM. If you use the
dataVolumeTemplate
field in the VM specification to prepare the PVC, the PVC shares the same lifecycle as the VM.
10.19.8.3. Creating an upload data volume
You can manually create a data volume with an upload
data source to use for uploading local disk images.
Procedure
Create a data volume configuration that specifies
spec: source: upload{}
:apiVersion: cdi.kubevirt.io/v1beta1 kind: DataVolume metadata: name: <upload-datavolume> 1 spec: source: upload: {} pvc: accessModes: - ReadWriteOnce resources: requests: storage: <2Gi> 2
Create the data volume by running the following command:
$ oc create -f <upload-datavolume>.yaml
10.19.8.4. Uploading a local disk image to a data volume
You can use the virtctl
CLI utility to upload a local disk image from a client machine to a data volume (DV) in your cluster. You can use a DV that already exists in your cluster or create a new DV during this procedure.
After you upload a local disk image, you can add it to a virtual machine.
Prerequisites
You must have one of the following:
- A raw virtual machine image file in either ISO or IMG format.
- A virtual machine image file in QCOW2 format.
For best results, compress your image file according to the following guidelines before you upload it:
Compress a raw image file by using
xz
orgzip
.NoteUsing a compressed raw image file results in the most efficient upload.
Compress a QCOW2 image file by using the method that is recommended for your client:
- If you use a Linux client, sparsify the QCOW2 file by using the virt-sparsify tool.
-
If you use a Windows client, compress the QCOW2 file by using
xz
orgzip
.
-
The
kubevirt-virtctl
package must be installed on the client machine. - The client machine must be configured to trust the OpenShift Container Platform router’s certificate.
Procedure
Identify the following items:
- The name of the upload data volume that you want to use. If this data volume does not exist, it is created automatically.
- The size of the data volume, if you want it to be created during the upload procedure. The size must be greater than or equal to the size of the disk image.
- The file location of the virtual machine disk image that you want to upload.
Upload the disk image by running the
virtctl image-upload
command. Specify the parameters that you identified in the previous step. For example:$ virtctl image-upload dv <datavolume_name> \ 1 --size=<datavolume_size> \ 2 --image-path=</path/to/image> \ 3
Note-
If you do not want to create a new data volume, omit the
--size
parameter and include the--no-create
flag. - When uploading a disk image to a PVC, the PVC size must be larger than the size of the uncompressed virtual disk.
-
To allow insecure server connections when using HTTPS, use the
--insecure
parameter. Be aware that when you use the--insecure
flag, the authenticity of the upload endpoint is not verified.
-
If you do not want to create a new data volume, omit the
Optional. To verify that a data volume was created, view all data volumes by running the following command:
$ oc get dvs
10.19.8.5. CDI supported operations matrix
This matrix shows the supported CDI operations for content types against endpoints, and which of these operations requires scratch space.
Content types | HTTP | HTTPS | HTTP basic auth | Registry | Upload |
---|---|---|---|---|---|
KubeVirt (QCOW2) |
✓ QCOW2 |
✓ QCOW2** |
✓ QCOW2 |
✓ QCOW2* |
✓ QCOW2* |
KubeVirt (RAW) |
✓ RAW |
✓ RAW |
✓ RAW |
✓ RAW* |
✓ RAW* |
✓ Supported operation
□ Unsupported operation
* Requires scratch space
** Requires scratch space if a custom certificate authority is required
10.19.8.6. Additional resources
- Configure preallocation mode to improve write performance for data volume operations.
10.19.9. Uploading a local disk image to a block storage persistent volume claim
You can upload a local disk image into a block persistent volume claim (PVC) by using the virtctl
command-line utility.
In this workflow, you create a local block device to use as a persistent volume, associate this block volume with an upload
data volume, and use virtctl
to upload the local disk image into the PVC.
10.19.9.1. Prerequisites
-
Install
virtctl
. - You might need to define a storage class or prepare CDI scratch space for this operation to complete successfully.
10.19.9.2. About data volumes
DataVolume
objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). You can create a data volume as either a standalone resource or by using the dataVolumeTemplate
field in the virtual machine (VM) specification.
-
VM disk PVCs that are prepared by using standalone data volumes maintain an independent lifecycle from the VM. If you use the
dataVolumeTemplate
field in the VM specification to prepare the PVC, the PVC shares the same lifecycle as the VM.
10.19.9.3. About block persistent volumes
A block persistent volume (PV) is a PV that is backed by a raw block device. These volumes do not have a file system and can provide performance benefits for virtual machines by reducing overhead.
Raw block volumes are provisioned by specifying volumeMode: Block
in the PV and persistent volume claim (PVC) specification.
10.19.9.4. Creating a local block persistent volume
If you intend to import a virtual machine image into block storage with a data volume, you must have an available local block persistent volume.
Create a local block persistent volume (PV) on a node by populating a file and mounting it as a loop device. You can then reference this loop device in a PV manifest as a Block
volume and use it as a block device for a virtual machine image.
Procedure
-
Log in as
root
to the node on which to create the local PV. This procedure usesnode01
for its examples. Create a file and populate it with null characters so that it can be used as a block device. The following example creates a file
loop10
with a size of 2Gb (20 100Mb blocks):$ dd if=/dev/zero of=<loop10> bs=100M count=20
Mount the
loop10
file as a loop device.$ losetup </dev/loop10>d3 <loop10> 1 2
Create a
PersistentVolume
manifest that references the mounted loop device.kind: PersistentVolume apiVersion: v1 metadata: name: <local-block-pv10> annotations: spec: local: path: </dev/loop10> 1 capacity: storage: <2Gi> volumeMode: Block 2 storageClassName: local 3 accessModes: - ReadWriteOnce persistentVolumeReclaimPolicy: Delete nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - <node01> 4
Create the block PV.
# oc create -f <local-block-pv10.yaml>1
- 1
- The file name of the persistent volume created in the previous step.
10.19.9.5. Creating an upload data volume
You can manually create a data volume with an upload
data source to use for uploading local disk images.
Procedure
Create a data volume configuration that specifies
spec: source: upload{}
:apiVersion: cdi.kubevirt.io/v1beta1 kind: DataVolume metadata: name: <upload-datavolume> 1 spec: source: upload: {} pvc: accessModes: - ReadWriteOnce resources: requests: storage: <2Gi> 2
Create the data volume by running the following command:
$ oc create -f <upload-datavolume>.yaml
10.19.9.6. Uploading a local disk image to a data volume
You can use the virtctl
CLI utility to upload a local disk image from a client machine to a data volume (DV) in your cluster. You can use a DV that already exists in your cluster or create a new DV during this procedure.
After you upload a local disk image, you can add it to a virtual machine.
Prerequisites
You must have one of the following:
- A raw virtual machine image file in either ISO or IMG format.
- A virtual machine image file in QCOW2 format.
For best results, compress your image file according to the following guidelines before you upload it:
Compress a raw image file by using
xz
orgzip
.NoteUsing a compressed raw image file results in the most efficient upload.
Compress a QCOW2 image file by using the method that is recommended for your client:
- If you use a Linux client, sparsify the QCOW2 file by using the virt-sparsify tool.
-
If you use a Windows client, compress the QCOW2 file by using
xz
orgzip
.
-
The
kubevirt-virtctl
package must be installed on the client machine. - The client machine must be configured to trust the OpenShift Container Platform router’s certificate.
Procedure
Identify the following items:
- The name of the upload data volume that you want to use. If this data volume does not exist, it is created automatically.
- The size of the data volume, if you want it to be created during the upload procedure. The size must be greater than or equal to the size of the disk image.
- The file location of the virtual machine disk image that you want to upload.
Upload the disk image by running the
virtctl image-upload
command. Specify the parameters that you identified in the previous step. For example:$ virtctl image-upload dv <datavolume_name> \ 1 --size=<datavolume_size> \ 2 --image-path=</path/to/image> \ 3
Note-
If you do not want to create a new data volume, omit the
--size
parameter and include the--no-create
flag. - When uploading a disk image to a PVC, the PVC size must be larger than the size of the uncompressed virtual disk.
-
To allow insecure server connections when using HTTPS, use the
--insecure
parameter. Be aware that when you use the--insecure
flag, the authenticity of the upload endpoint is not verified.
-
If you do not want to create a new data volume, omit the
Optional. To verify that a data volume was created, view all data volumes by running the following command:
$ oc get dvs
10.19.9.7. CDI supported operations matrix
This matrix shows the supported CDI operations for content types against endpoints, and which of these operations requires scratch space.
Content types | HTTP | HTTPS | HTTP basic auth | Registry | Upload |
---|---|---|---|---|---|
KubeVirt (QCOW2) |
✓ QCOW2 |
✓ QCOW2** |
✓ QCOW2 |
✓ QCOW2* |
✓ QCOW2* |
KubeVirt (RAW) |
✓ RAW |
✓ RAW |
✓ RAW |
✓ RAW* |
✓ RAW* |
✓ Supported operation
□ Unsupported operation
* Requires scratch space
** Requires scratch space if a custom certificate authority is required
10.19.9.8. Additional resources
- Configure preallocation mode to improve write performance for data volume operations.
10.19.10. Managing virtual machine snapshots
You can create and delete virtual machine (VM) snapshots for VMs, whether the VMs are powered off (offline) or on (online). You can only restore to a powered off (offline) VM. OpenShift Virtualization supports VM snapshots on the following:
- Red Hat OpenShift Data Foundation
- Any other cloud storage provider with the Container Storage Interface (CSI) driver that supports the Kubernetes Volume Snapshot API
Online snapshots have a default time deadline of five minutes (5m
) that can be changed, if needed.
Online snapshots are supported for virtual machines that have hot-plugged virtual disks. However, hot-plugged disks that are not in the virtual machine specification are not included in the snapshot.
To create snapshots of an online (Running state) VM with the highest integrity, install the QEMU guest agent.
The QEMU guest agent takes a consistent snapshot by attempting to quiesce the VM file system as much as possible, depending on the system workload. This ensures that in-flight I/O is written to the disk before the snapshot is taken. If the guest agent is not present, quiescing is not possible and a best-effort snapshot is taken. The conditions under which the snapshot was taken are reflected in the snapshot indications that are displayed in the web console or CLI.
10.19.10.1. About virtual machine snapshots
A snapshot represents the state and data of a virtual machine (VM) at a specific point in time. You can use a snapshot to restore an existing VM to a previous state (represented by the snapshot) for backup and disaster recovery or to rapidly roll back to a previous development version.
A VM snapshot is created from a VM that is powered off (Stopped state) or powered on (Running state).
When taking a snapshot of a running VM, the controller checks that the QEMU guest agent is installed and running. If so, it freezes the VM file system before taking the snapshot, and thaws the file system after the snapshot is taken.
The snapshot stores a copy of each Container Storage Interface (CSI) volume attached to the VM and a copy of the VM specification and metadata. Snapshots cannot be changed after creation.
With the VM snapshots feature, cluster administrators and application developers can:
- Create a new snapshot
- List all snapshots attached to a specific VM
- Restore a VM from a snapshot
- Delete an existing VM snapshot
10.19.10.1.1. Virtual machine snapshot controller and custom resource definitions (CRDs)
The VM snapshot feature introduces three new API objects defined as CRDs for managing snapshots:
-
VirtualMachineSnapshot
: Represents a user request to create a snapshot. It contains information about the current state of the VM. -
VirtualMachineSnapshotContent
: Represents a provisioned resource on the cluster (a snapshot). It is created by the VM snapshot controller and contains references to all resources required to restore the VM. -
VirtualMachineRestore
: Represents a user request to restore a VM from a snapshot.
The VM snapshot controller binds a VirtualMachineSnapshotContent
object with the VirtualMachineSnapshot
object for which it was created, with a one-to-one mapping.
10.19.10.2. Installing QEMU guest agent on a Linux virtual machine
The qemu-guest-agent
is widely available and available by default in Red Hat Enterprise Linux (RHEL) virtual machines (VMs). Install the agent and start the service.
To create snapshots of an online (Running state) VM with the highest integrity, install the QEMU guest agent.
The QEMU guest agent takes a consistent snapshot by attempting to quiesce the VM’s file system as much as possible, depending on the system workload. This ensures that in-flight I/O is written to the disk before the snapshot is taken. If the guest agent is not present, quiescing is not possible and a best-effort snapshot is taken. The conditions under which the snapshot was taken are reflected in the snapshot indications that are displayed in the web console or CLI.
Procedure
- Access the virtual machine command line through one of the consoles or by SSH.
Install the QEMU guest agent on the virtual machine:
$ yum install -y qemu-guest-agent
Ensure the service is persistent and start it:
$ systemctl enable --now qemu-guest-agent
Verification
Run the following command to verify that
AgentConnected
is listed in the VM spec:$ oc get vm <vm_name>
10.19.10.3. Installing QEMU guest agent on a Windows virtual machine
For Windows virtual machines, the QEMU guest agent is included in the VirtIO drivers. Install the drivers on an existing or a new Windows installation.
To create snapshots of an online (Running state) VM with the highest integrity, install the QEMU guest agent.
The QEMU guest agent takes a consistent snapshot by attempting to quiesce the VM’s file system as much as possible, depending on the system workload. This ensures that in-flight I/O is written to the disk before the snapshot is taken. If the guest agent is not present, quiescing is not possible and a best-effort snapshot is taken. The conditions under which the snapshot was taken are reflected in the snapshot indications that are displayed in the web console or CLI.
Procedure
-
In the Windows Guest Operating System (OS), use the File Explorer to navigate to the
guest-agent
directory in thevirtio-win
CD drive. -
Run the
qemu-ga-x86_64.msi
installer.
Verification
Run the following command to verify that the output contains the
QEMU Guest Agent
:$ net start
10.19.10.3.1. Installing VirtIO drivers on an existing Windows virtual machine
Install the VirtIO drivers from the attached SATA CD drive to an existing Windows virtual machine.
This procedure uses a generic approach to adding drivers to Windows. The process might differ slightly between versions of Windows. See the installation documentation for your version of Windows for specific installation steps.
Procedure
- Start the virtual machine and connect to a graphical console.
- Log in to a Windows user session.
Open Device Manager and expand Other devices to list any Unknown device.
-
Open the
Device Properties
to identify the unknown device. Right-click the device and select Properties. - Click the Details tab and select Hardware Ids in the Property list.
- Compare the Value for the Hardware Ids with the supported VirtIO drivers.
-
Open the
- Right-click the device and select Update Driver Software.
- Click Browse my computer for driver software and browse to the attached SATA CD drive, where the VirtIO drivers are located. The drivers are arranged hierarchically according to their driver type, operating system, and CPU architecture.
- Click Next to install the driver.
- Repeat this process for all the necessary VirtIO drivers.
- After the driver installs, click Close to close the window.
- Reboot the virtual machine to complete the driver installation.
10.19.10.4. Creating a virtual machine snapshot in the web console
You can create a virtual machine (VM) snapshot by using the web console.
To create snapshots of an online (Running state) VM with the highest integrity, install the QEMU guest agent.
The QEMU guest agent takes a consistent snapshot by attempting to quiesce the VM’s file system as much as possible, depending on the system workload. This ensures that in-flight I/O is written to the disk before the snapshot is taken. If the guest agent is not present, quiescing is not possible and a best-effort snapshot is taken. The conditions under which the snapshot was taken are reflected in the snapshot indications that are displayed in the web console or CLI.
The VM snapshot only includes disks that meet the following requirements:
- Must be either a data volume or persistent volume claim
- Belong to a storage class that supports Container Storage Interface (CSI) volume snapshots
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
-
If the virtual machine is running, click Actions
Stop to power it down. - Click the Snapshots tab and then click Take Snapshot.
- Fill in the Snapshot Name and optional Description fields.
- Expand Disks included in this Snapshot to see the storage volumes to be included in the snapshot.
- If your VM has disks that cannot be included in the snapshot and you still wish to proceed, select the I am aware of this warning and wish to proceed checkbox.
- Click Save.
10.19.10.5. Creating a virtual machine snapshot in the CLI
You can create a virtual machine (VM) snapshot for an offline or online VM by creating a VirtualMachineSnapshot
object. Kubevirt will coordinate with the QEMU guest agent to create a snapshot of the online VM.
To create snapshots of an online (Running state) VM with the highest integrity, install the QEMU guest agent.
The QEMU guest agent takes a consistent snapshot by attempting to quiesce the VM’s file system as much as possible, depending on the system workload. This ensures that in-flight I/O is written to the disk before the snapshot is taken. If the guest agent is not present, quiescing is not possible and a best-effort snapshot is taken. The conditions under which the snapshot was taken are reflected in the snapshot indications that are displayed in the web console or CLI.
Prerequisites
- Ensure that the persistent volume claims (PVCs) are in a storage class that supports Container Storage Interface (CSI) volume snapshots.
-
Install the OpenShift CLI (
oc
). - Optional: Power down the VM for which you want to create a snapshot.
Procedure
Create a YAML file to define a
VirtualMachineSnapshot
object that specifies the name of the newVirtualMachineSnapshot
and the name of the source VM.For example:
apiVersion: snapshot.kubevirt.io/v1beta1 kind: VirtualMachineSnapshot metadata: name: my-vmsnapshot 1 spec: source: apiGroup: kubevirt.io kind: VirtualMachine name: my-vm 2
Create the
VirtualMachineSnapshot
resource. The snapshot controller creates aVirtualMachineSnapshotContent
object, binds it to theVirtualMachineSnapshot
and updates thestatus
andreadyToUse
fields of theVirtualMachineSnapshot
object.$ oc create -f <my-vmsnapshot>.yaml
Optional: If you are taking an online snapshot, you can use the
wait
command and monitor the status of the snapshot:Enter the following command:
$ oc wait my-vm my-vmsnapshot --for condition=Ready
Verify the status of the snapshot:
-
InProgress
- The online snapshot operation is still in progress. -
Succeeded
- The online snapshot operation completed successfully. Failed
- The online snapshot operaton failed.NoteOnline snapshots have a default time deadline of five minutes (
5m
). If the snapshot does not complete successfully in five minutes, the status is set tofailed
. Afterwards, the file system will be thawed and the VM unfrozen but the status remainsfailed
until you delete the failed snapshot image.To change the default time deadline, add the
FailureDeadline
attribute to the VM snapshot spec with the time designated in minutes (m
) or in seconds (s
) that you want to specify before the snapshot operation times out.To set no deadline, you can specify
0
, though this is generally not recommended, as it can result in an unresponsive VM.If you do not specify a unit of time such as
m
ors
, the default is seconds (s
).
-
Verification
Verify that the
VirtualMachineSnapshot
object is created and bound withVirtualMachineSnapshotContent
. ThereadyToUse
flag must be set totrue
.$ oc describe vmsnapshot <my-vmsnapshot>
Example output
apiVersion: snapshot.kubevirt.io/v1beta1 kind: VirtualMachineSnapshot metadata: creationTimestamp: "2020-09-30T14:41:51Z" finalizers: - snapshot.kubevirt.io/vmsnapshot-protection generation: 5 name: mysnap namespace: default resourceVersion: "3897" selfLink: /apis/snapshot.kubevirt.io/v1beta1/namespaces/default/virtualmachinesnapshots/my-vmsnapshot uid: 28eedf08-5d6a-42c1-969c-2eda58e2a78d spec: source: apiGroup: kubevirt.io kind: VirtualMachine name: my-vm status: conditions: - lastProbeTime: null lastTransitionTime: "2020-09-30T14:42:03Z" reason: Operation complete status: "False" 1 type: Progressing - lastProbeTime: null lastTransitionTime: "2020-09-30T14:42:03Z" reason: Operation complete status: "True" 2 type: Ready creationTime: "2020-09-30T14:42:03Z" readyToUse: true 3 sourceUID: 355897f3-73a0-4ec4-83d3-3c2df9486f4f virtualMachineSnapshotContentName: vmsnapshot-content-28eedf08-5d6a-42c1-969c-2eda58e2a78d 4
- 1
- The
status
field of theProgressing
condition specifies if the snapshot is still being created. - 2
- The
status
field of theReady
condition specifies if the snapshot creation process is complete. - 3
- Specifies if the snapshot is ready to be used.
- 4
- Specifies that the snapshot is bound to a
VirtualMachineSnapshotContent
object created by the snapshot controller.
-
Check the
spec:volumeBackups
property of theVirtualMachineSnapshotContent
resource to verify that the expected PVCs are included in the snapshot.
10.19.10.6. Verifying online snapshot creation with snapshot indications
Snapshot indications are contextual information about online virtual machine (VM) snapshot operations. Indications are not available for offline virtual machine (VM) snapshot operations. Indications are helpful in describing details about the online snapshot creation.
Prerequisites
- To view indications, you must have attempted to create an online VM snapshot using the CLI or the web console.
Procedure
Display the output from the snapshot indications by doing one of the following:
-
For snapshots created with the CLI, view indicator output in the
VirtualMachineSnapshot
object YAML, in the status field. - For snapshots created using the web console, click VirtualMachineSnapshot > Status in the Snapshot details screen.
-
For snapshots created with the CLI, view indicator output in the
Verify the status of your online VM snapshot:
-
Online
indicates that the VM was running during online snapshot creation. -
NoGuestAgent
indicates that the QEMU guest agent was not running during online snapshot creation. The QEMU guest agent could not be used to freeze and thaw the file system, either because the QEMU guest agent was not installed or running or due to another error.
-
10.19.10.7. Restoring a virtual machine from a snapshot in the web console
You can restore a virtual machine (VM) to a previous configuration represented by a snapshot in the web console.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
-
If the virtual machine is running, click Actions
Stop to power it down. - Click the Snapshots tab. The page displays a list of snapshots associated with the virtual machine.
Choose one of the following methods to restore a VM snapshot:
- For the snapshot that you want to use as the source to restore the VM, click Restore.
-
Select a snapshot to open the Snapshot Details screen and click Actions
Restore VirtualMachineSnapshot.
- In the confirmation pop-up window, click Restore to restore the VM to its previous configuration represented by the snapshot.
10.19.10.8. Restoring a virtual machine from a snapshot in the CLI
You can restore an existing virtual machine (VM) to a previous configuration by using a VM snapshot. You can only restore from an offline VM snapshot.
Prerequisites
-
Install the OpenShift CLI (
oc
). - Power down the VM you want to restore to a previous state.
Procedure
Create a YAML file to define a
VirtualMachineRestore
object that specifies the name of the VM you want to restore and the name of the snapshot to be used as the source.For example:
apiVersion: snapshot.kubevirt.io/v1beta1 kind: VirtualMachineRestore metadata: name: my-vmrestore 1 spec: target: apiGroup: kubevirt.io kind: VirtualMachine name: my-vm 2 virtualMachineSnapshotName: my-vmsnapshot 3
Create the
VirtualMachineRestore
resource. The snapshot controller updates the status fields of theVirtualMachineRestore
object and replaces the existing VM configuration with the snapshot content.$ oc create -f <my-vmrestore>.yaml
Verification
Verify that the VM is restored to the previous state represented by the snapshot. The
complete
flag must be set totrue
.$ oc get vmrestore <my-vmrestore>
Example output
apiVersion: snapshot.kubevirt.io/v1beta1 kind: VirtualMachineRestore metadata: creationTimestamp: "2020-09-30T14:46:27Z" generation: 5 name: my-vmrestore namespace: default ownerReferences: - apiVersion: kubevirt.io/v1 blockOwnerDeletion: true controller: true kind: VirtualMachine name: my-vm uid: 355897f3-73a0-4ec4-83d3-3c2df9486f4f resourceVersion: "5512" selfLink: /apis/snapshot.kubevirt.io/v1beta1/namespaces/default/virtualmachinerestores/my-vmrestore uid: 71c679a8-136e-46b0-b9b5-f57175a6a041 spec: target: apiGroup: kubevirt.io kind: VirtualMachine name: my-vm virtualMachineSnapshotName: my-vmsnapshot status: complete: true 1 conditions: - lastProbeTime: null lastTransitionTime: "2020-09-30T14:46:28Z" reason: Operation complete status: "False" 2 type: Progressing - lastProbeTime: null lastTransitionTime: "2020-09-30T14:46:28Z" reason: Operation complete status: "True" 3 type: Ready deletedDataVolumes: - test-dv1 restoreTime: "2020-09-30T14:46:28Z" restores: - dataVolumeName: restore-71c679a8-136e-46b0-b9b5-f57175a6a041-datavolumedisk1 persistentVolumeClaim: restore-71c679a8-136e-46b0-b9b5-f57175a6a041-datavolumedisk1 volumeName: datavolumedisk1 volumeSnapshotName: vmsnapshot-28eedf08-5d6a-42c1-969c-2eda58e2a78d-volume-datavolumedisk1
10.19.10.9. Deleting a virtual machine snapshot in the web console
You can delete an existing virtual machine snapshot by using the web console.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select a virtual machine to open the VirtualMachine details page.
- Click the Snapshots tab. The page displays a list of snapshots associated with the virtual machine.
- Click the Options menu of the virtual machine snapshot that you want to delete and select Delete VirtualMachineSnapshot.
- In the confirmation pop-up window, click Delete to delete the snapshot.
10.19.10.10. Deleting a virtual machine snapshot in the CLI
You can delete an existing virtual machine (VM) snapshot by deleting the appropriate VirtualMachineSnapshot
object.
Prerequisites
-
Install the OpenShift CLI (
oc
).
Procedure
Delete the
VirtualMachineSnapshot
object. The snapshot controller deletes theVirtualMachineSnapshot
along with the associatedVirtualMachineSnapshotContent
object.$ oc delete vmsnapshot <my-vmsnapshot>
Verification
Verify that the snapshot is deleted and no longer attached to this VM:
$ oc get vmsnapshot
10.19.10.11. Additional resources
10.19.11. Moving a local virtual machine disk to a different node
Virtual machines that use local volume storage can be moved so that they run on a specific node.
You might want to move the virtual machine to a specific node for the following reasons:
- The current node has limitations to the local storage configuration.
- The new node is better optimized for the workload of that virtual machine.
To move a virtual machine that uses local storage, you must clone the underlying volume by using a data volume. After the cloning operation is complete, you can edit the virtual machine configuration so that it uses the new data volume, or add the new data volume to another virtual machine.
When you enable preallocation globally, or for a single data volume, the Containerized Data Importer (CDI) preallocates disk space during cloning. Preallocation enhances write performance. For more information, see Using preallocation for data volumes.
Users without the cluster-admin
role require additional user permissions to clone volumes across namespaces.
10.19.11.1. Cloning a local volume to another node
You can move a virtual machine disk so that it runs on a specific node by cloning the underlying persistent volume claim (PVC).
To ensure the virtual machine disk is cloned to the correct node, you must either create a new persistent volume (PV) or identify one on the correct node. Apply a unique label to the PV so that it can be referenced by the data volume.
The destination PV must be the same size or larger than the source PVC. If the destination PV is smaller than the source PVC, the cloning operation fails.
Prerequisites
- The virtual machine must not be running. Power down the virtual machine before cloning the virtual machine disk.
Procedure
Either create a new local PV on the node, or identify a local PV already on the node:
Create a local PV that includes the
nodeAffinity.nodeSelectorTerms
parameters. The following manifest creates a10Gi
local PV onnode01
.kind: PersistentVolume apiVersion: v1 metadata: name: <destination-pv> 1 annotations: spec: accessModes: - ReadWriteOnce capacity: storage: 10Gi 2 local: path: /mnt/local-storage/local/disk1 3 nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname operator: In values: - node01 4 persistentVolumeReclaimPolicy: Delete storageClassName: local volumeMode: Filesystem
Identify a PV that already exists on the target node. You can identify the node where a PV is provisioned by viewing the
nodeAffinity
field in its configuration:$ oc get pv <destination-pv> -o yaml
The following snippet shows that the PV is on
node01
:Example output
# ... spec: nodeAffinity: required: nodeSelectorTerms: - matchExpressions: - key: kubernetes.io/hostname 1 operator: In values: - node01 2 # ...
Add a unique label to the PV:
$ oc label pv <destination-pv> node=node01
Create a data volume manifest that references the following:
- The PVC name and namespace of the virtual machine.
- The label you applied to the PV in the previous step.
The size of the destination PV.
apiVersion: cdi.kubevirt.io/v1beta1 kind: DataVolume metadata: name: <clone-datavolume> 1 spec: source: pvc: name: "<source-vm-disk>" 2 namespace: "<source-namespace>" 3 pvc: accessModes: - ReadWriteOnce selector: matchLabels: node: node01 4 resources: requests: storage: <10Gi> 5
- 1
- The name of the new data volume.
- 2
- The name of the source PVC. If you do not know the PVC name, you can find it in the virtual machine configuration:
spec.volumes.persistentVolumeClaim.claimName
. - 3
- The namespace where the source PVC exists.
- 4
- The label that you applied to the PV in the previous step.
- 5
- The size of the destination PV.
Start the cloning operation by applying the data volume manifest to your cluster:
$ oc apply -f <clone-datavolume.yaml>
The data volume clones the PVC of the virtual machine into the PV on the specific node.
10.19.12. Expanding virtual storage by adding blank disk images
You can increase your storage capacity or create new data partitions by adding blank disk images to OpenShift Virtualization.
10.19.12.1. About data volumes
DataVolume
objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). You can create a data volume as either a standalone resource or by using the dataVolumeTemplate
field in the virtual machine (VM) specification.
-
VM disk PVCs that are prepared by using standalone data volumes maintain an independent lifecycle from the VM. If you use the
dataVolumeTemplate
field in the VM specification to prepare the PVC, the PVC shares the same lifecycle as the VM.
10.19.12.2. Creating a blank disk image with data volumes
You can create a new blank disk image in a persistent volume claim by customizing and deploying a data volume configuration file.
Prerequisites
- At least one available persistent volume.
-
Install the OpenShift CLI (
oc
).
Procedure
Edit the
DataVolume
manifest:apiVersion: cdi.kubevirt.io/v1beta1 kind: DataVolume metadata: name: blank-image-datavolume spec: source: blank: {} pvc: storageClassName: "hostpath" 1 accessModes: - ReadWriteOnce resources: requests: storage: 500Mi
- 1
- Optional: If you do not specify a storage class, the default storage class is applied.
Create the blank disk image by running the following command:
$ oc create -f <blank-image-datavolume>.yaml
10.19.12.3. Additional resources
- Configure preallocation mode to improve write performance for data volume operations.
10.19.13. Cloning a data volume using smart-cloning
Smart-cloning is a built-in feature of Red Hat OpenShift Data Foundation. Smart-cloning is faster and more efficient than host-assisted cloning.
You do not need to perform any action to enable smart-cloning, but you need to ensure your storage environment is compatible with smart-cloning to use this feature.
When you create a data volume with a persistent volume claim (PVC) source, you automatically initiate the cloning process. You always receive a clone of the data volume if your environment supports smart-cloning or not. However, you will only receive the performance benefits of smart cloning if your storage provider supports smart-cloning.
10.19.13.1. About data volumes
DataVolume
objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). You can create a data volume as either a standalone resource or by using the dataVolumeTemplate
field in the virtual machine (VM) specification.
-
VM disk PVCs that are prepared by using standalone data volumes maintain an independent lifecycle from the VM. If you use the
dataVolumeTemplate
field in the VM specification to prepare the PVC, the PVC shares the same lifecycle as the VM.
10.19.13.2. About smart-cloning
When a data volume is smart-cloned, the following occurs:
- A snapshot of the source persistent volume claim (PVC) is created.
- A PVC is created from the snapshot.
- The snapshot is deleted.
10.19.13.3. Cloning a data volume
Prerequisites
For smart-cloning to occur, the following conditions are required:
- Your storage provider must support snapshots.
- The source and target PVCs must be defined to the same storage class.
- The source and target PVCs share the same volumeMode.
-
The
VolumeSnapshotClass
object must reference the storage class defined to both the source and target PVCs.
Procedure
To initiate cloning of a data volume:
Create a YAML file for a
DataVolume
object that specifies the name of the new data volume and the name and namespace of the source PVC. In this example, because you specify the storage API, there is no need to specify accessModes or volumeMode. The optimal values will be calculated for you automatically.apiVersion: cdi.kubevirt.io/v1beta1 kind: DataVolume metadata: name: <cloner-datavolume> 1 spec: source: pvc: namespace: "<source-namespace>" 2 name: "<my-favorite-vm-disk>" 3 storage: 4 resources: requests: storage: <2Gi> 5
Start cloning the PVC by creating the data volume:
$ oc create -f <cloner-datavolume>.yaml
NoteData volumes prevent a virtual machine from starting before the PVC is prepared, so you can create a virtual machine that references the new data volume while the PVC clones.
10.19.13.4. Additional resources
- Cloning the persistent volume claim of a virtual machine disk into a new data volume
- Configure preallocation mode to improve write performance for data volume operations.
- Customizing the storage profile
10.19.14. Hot plugging virtual disks
You can add or remove virtual disks without stopping your virtual machine (VM) or virtual machine instance (VMI).
10.19.14.1. About hot plugging virtual disks
When you hot plug a virtual disk, you attach a virtual disk to a virtual machine instance while the virtual machine is running.
When you hot unplug a virtual disk, you detach a virtual disk from a virtual machine instance while the virtual machine is running.
Only data volumes and persistent volume claims (PVCs) can be hot plugged and hot unplugged. You cannot hot plug or hot unplug container disks.
After you hot plug a virtual disk, it remains attached until you detach it, even if you restart the virtual machine.
In the web console, hot-plugged volumes are marked by a "persistent hotplug" label on the disk in the disk list (VirtualMachine Details
10.19.14.2. About virtio-scsi
In OpenShift Virtualization, each virtual machine (VM) has a virtio-scsi
controller so that hot plugged disks can use a scsi
bus. The virtio-scsi
controller overcomes the limitations of virtio
while retaining its performance advantages. It is highly scalable and supports hot plugging over 4 million disks.
Regular virtio
is not available for hot plugged disks because it is not scalable: each virtio
disk uses one of the limited PCI Express (PCIe) slots in the VM. PCIe slots are also used by other devices and must be reserved in advance, therefore slots might not be available on demand.
10.19.14.3. Hot plugging a virtual disk using the CLI
Hot plug virtual disks that you want to attach to a virtual machine instance (VMI) while a virtual machine is running.
Prerequisites
- You must have a running virtual machine to hot plug a virtual disk.
- You must have at least one data volume or persistent volume claim (PVC) available for hot plugging.
Procedure
Hot plug a virtual disk by running the following command:
$ virtctl addvolume <virtual-machine|virtual-machine-instance> --volume-name=<datavolume|PVC> \ [--persist] [--serial=<label-name>]
-
Use the optional
--persist
flag to add the hot plugged disk to the virtual machine specification as a permanently mounted virtual disk. Stop, restart, or reboot the virtual machine to permanently mount the virtual disk. After specifying the--persist
flag, you can no longer hot plug or hot unplug the virtual disk. The--persist
flag applies to virtual machines, not virtual machine instances. -
The optional
--serial
flag allows you to add an alphanumeric string label of your choice. This helps you to identify the hot plugged disk in a guest virtual machine. If you do not specify this option, the label defaults to the name of the hot plugged data volume or PVC.
-
Use the optional
10.19.14.4. Hot unplugging a virtual disk using the CLI
Hot unplug virtual disks that you want to detach from a virtual machine instance (VMI) while a virtual machine is running.
Prerequisites
- Your virtual machine must be running.
- You must have at least one data volume or persistent volume claim (PVC) available and hot plugged.
Procedure
Hot unplug a virtual disk by running the following command:
$ virtctl removevolume <virtual-machine|virtual-machine-instance> --volume-name=<datavolume|PVC>
10.19.14.5. Hot plugging a virtual disk using the web console
Hot plug virtual disks that you want to attach to a virtual machine instance (VMI) while a virtual machine is running. When you hot plug a virtual disk, it remains attached to the VMI until you unplug it.
Prerequisites
- You must have a running virtual machine to hot plug a virtual disk.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select the running virtual machine to which you want to hot plug a virtual disk.
-
On the VirtualMachine details page, click Configuration
Disks. - Click Add disk.
- In the Add disk (hot plugged) window, fill in the information for the virtual disk that you want to hot plug.
- Click Save.
10.19.14.6. Hot unplugging a virtual disk using the web console
Hot unplug virtual disks that you want to detach from a virtual machine instance (VMI) while a virtual machine is running.
Prerequisites
- Your virtual machine must be running with a hot plugged disk attached.
Procedure
-
Click Virtualization
VirtualMachines from the side menu. - Select the running virtual machine with the disk you want to hot unplug to open the VirtualMachine details page.
-
Click Configuration
Disks. - Click the Options menu beside the virtual disk that you want to hot unplug and select Detach.
- Click Detach.
10.19.15. Using container disks with virtual machines
You can build a virtual machine image into a container disk and store it in your container registry. You can then import the container disk into persistent storage for a virtual machine or attach it directly to the virtual machine for ephemeral storage.
If you use large container disks, I/O traffic might increase, impacting worker nodes. This can lead to unavailable nodes. You can resolve this by:
10.19.15.1. About container disks
A container disk is a virtual machine image that is stored as a container image in a container image registry. You can use container disks to deliver the same disk images to multiple virtual machines and to create large numbers of virtual machine clones.
A container disk can either be imported into a persistent volume claim (PVC) by using a data volume that is attached to a virtual machine, or attached directly to a virtual machine as an ephemeral containerDisk
volume.
10.19.15.1.1. Importing a container disk into a PVC by using a data volume
Use the Containerized Data Importer (CDI) to import the container disk into a PVC by using a data volume. You can then attach the data volume to a virtual machine for persistent storage.
10.19.15.1.2. Attaching a container disk to a virtual machine as a containerDisk
volume
A containerDisk
volume is ephemeral. It is discarded when the virtual machine is stopped, restarted, or deleted. When a virtual machine with a containerDisk
volume starts, the container image is pulled from the registry and hosted on the node that is hosting the virtual machine.
Use containerDisk
volumes for read-only file systems such as CD-ROMs or for disposable virtual machines.
Using containerDisk
volumes for read-write file systems is not recommended because the data is temporarily written to local storage on the hosting node. This slows live migration of the virtual machine, such as in the case of node maintenance, because the data must be migrated to the destination node. Additionally, all data is lost if the node loses power or otherwise shuts down unexpectedly.
10.19.15.2. Preparing a container disk for virtual machines
You must build a container disk with a virtual machine image and push it to a container registry before it can used with a virtual machine. You can then either import the container disk into a PVC using a data volume and attach it to a virtual machine, or you can attach the container disk directly to a virtual machine as an ephemeral containerDisk
volume.
The size of a disk image inside a container disk is limited by the maximum layer size of the registry where the container disk is hosted.
For Red Hat Quay, you can change the maximum layer size by editing the YAML configuration file that is created when Red Hat Quay is first deployed.
Prerequisites
-
Install
podman
if it is not already installed. - The virtual machine image must be either QCOW2 or RAW format.
Procedure
Create a Dockerfile to build the virtual machine image into a container image. The virtual machine image must be owned by QEMU, which has a UID of
107
, and placed in the/disk/
directory inside the container. Permissions for the/disk/
directory must then be set to0440
.The following example uses the Red Hat Universal Base Image (UBI) to handle these configuration changes in the first stage, and uses the minimal
scratch
image in the second stage to store the result:$ cat > Dockerfile << EOF FROM registry.access.redhat.com/ubi8/ubi:latest AS builder ADD --chown=107:107 <vm_image>.qcow2 /disk/ 1 RUN chmod 0440 /disk/* FROM scratch COPY --from=builder /disk/* /disk/ EOF
- 1
- Where <vm_image> is the virtual machine image in either QCOW2 or RAW format.
To use a remote virtual machine image, replace<vm_image>.qcow2
with the complete url for the remote image.
Build and tag the container:
$ podman build -t <registry>/<container_disk_name>:latest .
Push the container image to the registry:
$ podman push <registry>/<container_disk_name>:latest
If your container registry does not have TLS you must add it as an insecure registry before you can import container disks into persistent storage.
10.19.15.3. Disabling TLS for a container registry to use as insecure registry
You can disable TLS (transport layer security) for one or more container registries by editing the insecureRegistries
field of the HyperConverged
custom resource.
Prerequisites
-
Log in to the cluster as a user with the
cluster-admin
role.
Procedure
Edit the
HyperConverged
custom resource and add a list of insecure registries to thespec.storageImport.insecureRegistries
field.apiVersion: hco.kubevirt.io/v1beta1 kind: HyperConverged metadata: name: kubevirt-hyperconverged namespace: openshift-cnv spec: storageImport: insecureRegistries: 1 - "private-registry-example-1:5000" - "private-registry-example-2:5000"
- 1
- Replace the examples in this list with valid registry hostnames.
10.19.15.4. Next steps
- Import the container disk into persistent storage for a virtual machine.
-
Create a virtual machine that uses a
containerDisk
volume for ephemeral storage.
10.19.16. Preparing CDI scratch space
10.19.16.1. About data volumes
DataVolume
objects are custom resources that are provided by the Containerized Data Importer (CDI) project. Data volumes orchestrate import, clone, and upload operations that are associated with an underlying persistent volume claim (PVC). You can create a data volume as either a standalone resource or by using the dataVolumeTemplate
field in the virtual machine (VM) specification.
-
VM disk PVCs that are prepared by using standalone data volumes maintain an independent lifecycle from the VM. If you use the
dataVolumeTemplate
field in the VM specification to prepare the PVC, the PVC shares the same lifecycle as the VM.
10.19.16.2. About scratch space
The Containerized Data Importer (CDI) requires scratch space (temporary storage) to complete some operations, such as importing and uploading virtual machine images. During this process, CDI provisions a scratch space PVC equal to the size of the PVC backing the destination data volume (DV). The scratch space PVC is deleted after the operation completes or aborts.
You can define the storage class that is used to bind the scratch space PVC in the spec.scratchSpaceStorageClass
field of the HyperConverged
custom resource.
If the defined storage class does not match a storage class in the cluster, then the default storage class defined for the cluster is used. If there is no default storage class defined in the cluster, the storage class used to provision the original DV or PVC is used.
CDI requires requesting scratch space with a file
volume mode, regardless of the PVC backing the origin data volume. If the origin PVC is backed by block
volume mode, you must define a storage class capable of provisioning file
volume mode PVCs.
Manual provisioning
If there are no storage classes, CDI uses any PVCs in the project that match the size requirements for the image. If there are no PVCs that match these requirements, the CDI import pod remains in a Pending state until an appropriate PVC is made available or until a timeout function kills the pod.
10.19.16.3. CDI operations that require scratch space
Type | Reason |
---|---|
Registry imports | CDI must download the image to a scratch space and extract the layers to find the image file. The image file is then passed to QEMU-IMG for conversion to a raw disk. |
Upload image | QEMU-IMG does not accept input from STDIN. Instead, the image to upload is saved in scratch space before it can be passed to QEMU-IMG for conversion. |
HTTP imports of archived images | QEMU-IMG does not know how to handle the archive formats CDI supports. Instead, the image is unarchived and saved into scratch space before it is passed to QEMU-IMG. |
HTTP imports of authenticated images | QEMU-IMG inadequately handles authentication. Instead, the image is saved to scratch space and authenticated before it is passed to QEMU-IMG. |
HTTP imports of custom certificates | QEMU-IMG inadequately handles custom certificates of HTTPS endpoints. Instead, CDI downloads the image to scratch space before passing the file to QEMU-IMG. |
10.19.16.4. Defining a storage class
You can define the storage class that the Containerized Data Importer (CDI) uses when allocating scratch space by adding the spec.scratchSpaceStorageClass
field to the HyperConverged
custom resource (CR).
Prerequisites
-
Install the OpenShift CLI (
oc
).
Procedure
Edit the
HyperConverged
CR by running the following command:$ oc edit hco -n openshift-cnv kubevirt-hyperconverged
Add the
spec.scratchSpaceStorageClass
field to the CR, setting the value to the name of a storage class that exists in the cluster:apiVersion: hco.kubevirt.io/v1beta1 kind: HyperConverged metadata: name: kubevirt-hyperconverged spec: scratchSpaceStorageClass: "<storage_class>" 1
- 1
- If you do not specify a storage class, CDI uses the storage class of the persistent volume claim that is being populated.
-
Save and exit your default editor to update the
HyperConverged
CR.
10.19.16.5. CDI supported operations matrix
This matrix shows the supported CDI operations for content types against endpoints, and which of these operations requires scratch space.
Content types | HTTP | HTTPS | HTTP basic auth | Registry | Upload |
---|---|---|---|---|---|
KubeVirt (QCOW2) |
✓ QCOW2 |
✓ QCOW2** |
✓ QCOW2 |
✓ QCOW2* |
✓ QCOW2* |
KubeVirt (RAW) |
✓ RAW |
✓ RAW |
✓ RAW |
✓ RAW* |
✓ RAW* |
✓ Supported operation
□ Unsupported operation
* Requires scratch space
** Requires scratch space if a custom certificate authority is required
10.19.16.6. Additional resources
10.19.17. Re-using persistent volumes
To re-use a statically provisioned persistent volume (PV), you must first reclaim the volume. This involves deleting the PV so that the storage configuration can be re-used.
10.19.17.1. About reclaiming statically provisioned persistent volumes
When you reclaim a persistent volume (PV), you unbind the PV from a persistent volume claim (PVC) and delete the PV. Depending on the underlying storage, you might need to manually delete the shared storage.
You can then re-use the PV configuration to create a PV with a different name.
Statically provisioned PVs must have a reclaim policy of Retain
to be reclaimed. If they do not, the PV enters a failed state when the PVC is unbound from the PV.
The Recycle
reclaim policy is deprecated in OpenShift Container Platform 4.
10.19.17.2. Reclaiming statically provisioned persistent volumes
Reclaim a statically provisioned persistent volume (PV) by unbinding the persistent volume claim (PVC) and deleting the PV. You might also need to manually delete the shared storage.
Reclaiming a statically provisioned PV is dependent on the underlying storage. This procedure provides a general approach that might need to be customized depending on your storage.
Procedure
Ensure that the reclaim policy of the PV is set to
Retain
:Check the reclaim policy of the PV:
$ oc get pv <pv_name> -o yaml | grep 'persistentVolumeReclaimPolicy'
If the
persistentVolumeReclaimPolicy
is not set toRetain
, edit the reclaim policy with the following command:$ oc patch pv <pv_name> -p '{"spec":{"persistentVolumeReclaimPolicy":"Retain"}}'
Ensure that no resources are using the PV:
$ oc describe pvc <pvc_name> | grep 'Mounted By:'
Remove any resources that use the PVC before continuing.
Delete the PVC to release the PV:
$ oc delete pvc <pvc_name>
Optional: Export the PV configuration to a YAML file. If you manually remove the shared storage later in this procedure, you can refer to this configuration. You can also use
spec
parameters in this file as the basis to create a new PV with the same storage configuration after you reclaim the PV:$ oc get pv <pv_name> -o yaml > <file_name>.yaml
Delete the PV:
$ oc delete pv <pv_name>
Optional: Depending on the storage type, you might need to remove the contents of the shared storage folder:
$ rm -rf <path_to_share_storage>
Optional: Create a PV that uses the same storage configuration as the deleted PV. If you exported the reclaimed PV configuration earlier, you can use the
spec
parameters of that file as the basis for a new PV manifest:NoteTo avoid possible conflict, it is good practice to give the new PV object a different name than the one that you deleted.
$ oc create -f <new_pv_name>.yaml
Additional resources
- Configuring local storage for virtual machines
- The OpenShift Container Platform Storage documentation has more information on Persistent Storage.
10.19.18. Expanding a virtual machine disk
You can enlarge the size of a virtual machine’s (VM) disk to provide a greater storage capacity by resizing the disk’s persistent volume claim (PVC).
However, you cannot reduce the size of a VM disk.
10.19.18.1. Enlarging a virtual machine disk
Virtual machine (VM) disk enlargement makes extra space available to the virtual machine. However, it is the responsibility of the VM owner to decide how to consume the storage.
If the disk is a Filesystem
PVC, the matching file expands to the remaining size while reserving some space for file system overhead.
Procedure
Edit the
PersistentVolumeClaim
manifest of the VM disk that you want to expand:$ oc edit pvc <pvc_name>
Update the disk size:
apiVersion: v1 kind: PersistentVolumeClaim metadata: name: vm-disk-expand spec: accessModes: - ReadWriteMany resources: requests: storage: 3Gi 1 # ...
- 1
- Specify the new disk size.