V2V Guide

Procedure 3.2. Preparing to convert a virtual machine running Linux

1. Obtain the software.
   As part of the conversion process, virt-v2v may install a new kernel and drivers on the virtual machine. If the virtual machine being converted is registered to Red Hat Subscription Management (RHSM), the required packages will be automatically downloaded. For environments where Red Hat Subscription Management (RHSM) is not available, the virt-v2v.conf file references a list of RPMs used for this purpose. The RPMs relevant to your virtual machine must be downloaded manually from the Red Hat Customer Portal and made available in the directory specified by the path-root configuration element, which by default is /var/lib/virt-v2v/software/. virt-v2v will display an error similar to Example 3.1, “Missing Package error” if the software it depends upon for a particular conversion is not available.

   Example 3.1. Missing Package error

   virt-v2v: Installation failed because the following files referenced in the configuration file are required, but missing:
   rhel/6/kernel-2.6.32-128.el6.x86_64.rpm
   rhel/6/ecryptfs-utils-82-6.el6.x86_64.rpm
   rhel/6/ecryptfs-utils-82-6.el6.i686.rpm
   

2. To obtain the relevant RPMs for your environment, repeat these steps for each missing package:
   1. Log in to the Red Hat Customer Portal: https://access.redhat.com/.
   2. In the Red Hat Customer Portal, select Downloads > Product Downloads > Red Hat Enterprise Linux.
   3. Select the desired Product Variant, Version, and select the Packages tab. In the Filter field, type the package name exactly matching the one shown in the error message. For the example shown in Example 3.1, “Missing Package error”, the first package is kernel-2.6.32-128.el6.x86_64
   4. A list of packages displays. Select the package name identical to the one in the error message. This opens the details page, which contains a detailed description of the package. Alternatively, to download the most recent version of a package, select Download Latest next to the desired package.
   5. Save the downloaded package to the appropriate directory in /var/lib/virt-v2v/software. For Red Hat Enterprise Linux 6, the directory is /var/lib/virt-v2v/software/rhel/6.

Procedure 3.3. Preparing to convert a local Xen virtual machine

• Obtain the XML for the virtual machine.
  virt-v2v uses a libvirt domain description to determine the current configuration of the virtual machine, including the location of its storage. Before starting the conversion, obtain the XML from the host running the virtual machine with the following command:

  virsh dumpxml guest_name > guest_name.xml

  This will require booting into a Xen kernel to obtain the XML, as libvirt needs to connect to a running Xen hypervisor to obtain its metadata. The conversion process is optimized for KVM, so obtaining domain data while running a Xen kernel, then performing the conversion using a KVM kernel will be more efficient than running the conversion on a Xen kernel.

1. Install the libguestfs-winsupport package on the host running virt-v2v. This package provides support for NTFS, which is used by many Windows systems. The libguestfs-winsupport package is provided by the RHEL V2VWIN (v. 6 for 64-bit x86_64) channel. Ensure your system is subscribed to this channel, then run the following command as root:

   yum install libguestfs-winsupport

   If you attempt to convert a virtual machine using NTFS without the libguestfs-winsupport package installed, the conversion will fail. An error message similar to Example 3.2, “Error message when converting a Windows virtual machine without libguestfs-winsupport installed” will be shown.

   Example 3.2. Error message when converting a Windows virtual machine without libguestfs-winsupport installed

   No operating system could be detected inside this disk image.
   
   This may be because the file is not a disk image, or is not a virtual machine
   image, or because the OS type is not understood by virt-inspector.
   
   If you feel this is an error, please file a bug report including as much
   information about the disk image as possible.

2. Install the virtio-win package on the host running virt-v2v. This package provides paravirtualized block and network drivers for Windows guests. The virtio-win package is provided by the RHEL Server Supplementary (v. 6 64-bit x86_64) channel. Ensure your system is subscribed to this channel, then run the following command as root:

   yum install virtio-win

   If you attempt to convert a virtual machine running Windows without the virtio-win package installed, the conversion will fail. An error message similar to Example 3.3, “Error message when converting a Windows virtual machine without virtio-win installed” will be shown.

   Example 3.3. Error message when converting a Windows virtual machine without virtio-win installed

   virt-v2v: Installation failed because the following files referenced in the configuration file are required, but missing: /usr/share/virtio-win/drivers/i386/Win2008

Procedure 4.2. Preparing to convert a virtual machine

1. Create an NFS export domain. virt-v2v can transfer the converted virtual machine directly to an NFS export storage domain. From the export storage domain, the virtual machine can be imported into a Red Hat Enterprise Virtualization data center. The storage domain must be mountable by the machine running virt-v2v. When exporting to a Red Hat Enterprise Virtualization export domain, virt-v2v must run as root.

   Note

   The export storage domain is accessed as an NFS share. By default, Red Hat Enterprise Linux 6 uses NFSv4, which does not require further configuration. However, for NFSv2 and NFSv3 clients, the rpcbind and nfslock services must be running on the host used to run virt-v2v. The network must also be configured to allow NFS access to the storage server. For more details refer to the Red Hat Enterprise Linux Storage Administration Guide.
2. Specify network mappings in virt-v2v.conf. This step is optional, and is not required for most use cases.
   If your virtual machine has multiple network interfaces, /etc/virt-v2v.conf must be edited to specify the network mapping for all interfaces. You can specify an alternative virt-v2v.conf file with the -f parameter. If you are converting to a virtual machine for output to both libvirt and Red Hat Enterprise Virtualization, separate virt-v2v.conf files should be used for each conversion. This is because a converted bridge will require different configuration depending on the output type (libvirt or Red Hat Enterprise Virtualization).
   If your virtual machine only has a single network interface, it is simpler to use the --network or --bridge parameters, rather than modifying virt-v2v.conf.
3. Create a profile for the conversion in virt-v2v.conf. This step is optional. Profiles specify a conversion method, storage location, output format and allocation policy. When a profile is defined, it can be called using --profile rather than individually providing the -o, -os, -of and -oa parameters. See virt-v2v.conf(5) for details.

Procedure 4.7. Importing and running the converted virtual machine

1. In the Red Hat Enterprise Virtualization Administration Portal, select the export domain from the Storage tab. The export domain must have a status of Active.
2. Select the VM Import tab in the details pane to list the available virtual machines to import.
3. Select one or more virtual machines and click Import. The Import Virtual Machine(s) window will open.
4. In the drop-down menus, select the select the Default Storage Domain, Cluster, and Cluster Quota in the data center.
5. Select the Collapse Snapshots check box to remove snapshot restore points and include templates in template-based virtual machines. Click OK to import the virtual machines.

Procedure 4.8. Scripting the v2v process

1. Use virt-v2v to convert the virtual machines and copy them to the export storage domain. This step must be run on a Linux host. The process is detailed in Section 4.3.2, “Converting a virtual machine”.
2. Once the conversion is complete, use the Red Hat Enterprise Virtualization Administration Portal to import the virtual machines from the export storage domain. This step must be run on the Red Hat Enterprise Virtualization Manager server.
   For more information on importing a virtual machine with the Red Hat Enterprise Virtualization Administration Portal, see the Red Hat Enterprise Virtualization Administration Guide.
   

   Figure 4.4. Importing a virtual machine with the Red Hat Enterprise Virtualization Administration Portal

   Alternatively, the Python SDK or the command line can also be used to import the virtual machines from the export storage domain:
   To import the virtual machines using the SDK, use the following:

   Example 4.3. Importing virtual machines from the export storage domain using the SDK

   api = API(url="http(s)://...:.../api",
             username="...",
             password="...",
             filter=False,
             debug=True)
   
   
   sd = api.storagedomains.get(id="from-sd-id")
   import_candidate = sd.vms.get(id="vm-to-import")
   import_candidate.import_vm(action=params.Action(
   cluster=api.clusters.get(id="to-cluster-id"),
   storage_domain=api.storagedomains.get(id="to-sd-id")))

   Note

   When using the SDK method, entities can also be fetched and passed using name=.
   To import the virtual machines using the command line, connect to the Red Hat Enterprise Virtualization Manager shell and use the following command:

   Example 4.4. Importing virtual machines from the export storage domain using the command line

   action vm "vm-to-import" import_vm --storagedomain-identifier "from-sd-id" --cluster-id "to-cluster-id" --storage_domain-id "to-sd-id"

   Note

   When using the command line method, entities can also be fetched and passed using -name.

Procedure 4.9. Configuring and running the scripted bulk v2v process

1. Ensure the REST API is enabled on the Red Hat Enterprise Virtualization Manager, and it is accessible from the Linux host running the v2v process. For more information about the REST API, see the Red Hat Enterprise Virtualization REST API Guide Guide.
2. On the Linux host, create the file v2v.sh with the following contents. Ensure you edit the script to contain appropriate values for your environment.

   Example 4.5. Single host v2v script

   #!/bin/sh
   # Declare all VMs to import
   XENDOMAINS=("rhelxen" "rhel5")
   KVMDOMAINS=("rhelkvm")
   VMWAREVMS=("rhel54vmware")
   
   # Iterate through each Xen domain, performing the conversion
   for domain in ${XENDOMAINS[@]}
   do
           virt-v2v -ic xen:///localhost -o rhev -os storage.example.com:/exportdomain --network rhevm $domain
   done
   
   # Iterate through each KVM domain, performing the conversion
   for domain in ${KVMDOMAINS[@]}
   do
           virt-v2v -o rhev -os storage.example.com:/exportdomain --network rhevm $domain
   done
   
   # Iterate through each VMware VM, performing the conversion
   for vm in ${VMWAREVMS[@]}
   do
           virt-v2v -ic esx://esx.example.com/?no_verify=1 -o rhev -os storage.example.com:/exportdomain --network rhevm $vm
   done
   
   
   # Call the import VM procedure remotely on the RHEV Manager
   
   export BASE_URL='https://[rhevm-host]'
   export HTTP_USER='user@internal'
   export HTTP_PASSWORD='password'
   
   curl -o rhevm.cer http://[rhevm-host]/ca.crt
   
   # Get the export storage domains
   
   curl -X GET -H "Accept: application/xml" -u "${HTTP_USER}:${HTTP_PASSWORD}" --cacert rhevm.cer ${BASE_URL}/api/storagedomains?search=nfs_export -o exportdomain
   EXPORT_DOMAIN=`xpath exportdomain '/storage_domains/storage_domain/@id' | sed -e 's/ id=//' | sed -e 's/"//g'`
   
   # Get the datacenter
   
   curl -X GET -H "Accept: application/xml" -u "${HTTP_USER}:${HTTP_PASSWORD}" --cacert rhevm.cer ${BASE_URL}/api/datacenters?search=NFS -o dc
   DC=`xpath dc '/data_centers/data_center/@id' | sed -e 's/ id=//' | sed -e 's/"//g'`
   
   # Get the cluster
   
   curl -X GET -H "Accept: application/xml" -u "${HTTP_USER}:${HTTP_PASSWORD}" --cacert rhevm.cer ${BASE_URL}/api/clusters?search=NFS -o cluster
   CLUSTER_ELEMENT=`xpath cluster '/clusters/cluster/@id' | sed -e 's/ id=//' | sed -e 's/"//g'`
   
   # List contents of export storage domain
   
   curl -X GET -H "Accept: application/xml" -u "${HTTP_USER}:${HTTP_PASSWORD}" --cacert rhevm.cer ${BASE_URL}/api/storagedomains/${EXPORT_DOMAIN}/vms -o vms
   
   # For each vm, export
   VMS=`xpath vms '/vms/vm/actions/link[@rel="import"]/@href' | sed -e 's/ href="//g' | sed -e 's/"/ /g'`
   
   for vms in $VMS
   do
           curl -v -u "${HTTP_USER}:${HTTP_PASSWORD}" -H "Content-type: application/xml" -d '<action><cluster><name>cluster_name</name></cluster><storage_domain><name>data_domain</name></storage_domain><overwrite>true</overwrite><discard_snapshots>true</discard_snapshots></action>' --cacert rhevm.cer ${BASE_URL}$vms
   done
   
   

   Note

   Use the POST method to export virtual machines with the REST API. For more information about using the REST API, see the Red Hat Enterprise Virtualization REST API Guide.
3. Run the v2v.sh script. It can take several hours to convert and import a large number of virtual machines.

1. As root, edit the sshd_config file in /etc/ssh/sshd_config:

   nano /etc/ssh/sshd_config

2. Add a line in the Authentication section of the file that says PermitRootLogin yes. This line may already exist and be commented out with a "#". In this case, remove the "#".

   # Authentication:
   #LoginGraceTime 2m
   PermitRootLogin yes
   #StrictModes yes
   #MaxAuthTries 6
   #MaxSessions 10

3. Save the updated /etc/ssh/sshd_config file.
4. Restart the SSH server:

   service sshd restart

1. As root, edit /etc/virt-v2v.conf:

   nano /etc/virt-v2v.conf

2. Scroll to the end of the file. Before the final </virt-v2v>, add the following:

   <profile name="myrhev">
   <method>rhev</method>
   <storage format="raw" allocation="preallocated">
   nfs.share.com:/export1
   </storage>
   <network type="default">
   <network type="network" name="rhevm"/>
   </network>
   </profile>
   

   Where:

   • Profile Name is an arbitrary, descriptive target profile name.
   • Method is the destination hypervisor type (rhev or libvirt).
   • Storage Format is the output storage format, either raw or qcow2.
   • Allocation is the output allocation policy, either preallocated or sparse.
   • Network type specifies the network to which a network interface should be connected when imported into Red Hat Enterprise Virtualization. The first network type entry contains details about network configuration before conversion, the second network type entry maps to an after conversion configuration. In the given example, any detected network card is to be mapped to the managed network called rhevm.

   Important

   The value associated with the <storage format> tag (in the above example "nfs.share.com:/export1") must match the value associated with the <method> tag. In this example, since the output method is "rhev", the value associated with storage must be an initialized NFS share. For the libvirt method, the storage format value must be an initialized storage domain that exists locally on the conversion server, for example "default".

1. virt-v2v installs VirtIO block drivers.
2. virt-v2v installs the CDUpgrader utility.
3. virt-v2v copies VirtIO block and network drivers to %SystemRoot%\Drivers\VirtIO. The virtio-win package does not include network drivers for Windows 7 and Windows XP. For those operating systems, the rtl8139 network drivers are used. rtl8139 support must be already available in the guest virtual machine.
4. virt-v2v adds %SystemRoot%\Drivers\VirtIO to DevicePath, meaning this directory is automatically searched for drivers when a new device is detected.
5. virt-v2v makes registry changes to include the VirtIO block drivers in the CriticalDeviceDatabase section of the registry, and ensure the CDUpgrader service is started at the next boot.

1. The virtual machine is imported and run on the Manager. See the Red Hat Enterprise Virtualization Administration Guide for details.

   Important

   The first boot stage can take several minutes to run, and must not be interrupted. It will run automatically without any administrator intervention other than starting the virtual machine. To ensure the process is not interrupted, no user should log in to the virtual machine until it has quiesced. You can check for this in the Manager GUI.
2. If the guest tools ISO has been uploaded to the Manager, as detailed in Section 4.3.1.2, “Preparing to convert a virtual machine running Windows”, the Manager attaches the guest tools CD to the virtual machine.
3. CDUpgrader detects the guest tools ISO and installs all the VirtIO drivers from it, including additional tools that are not included in virtio-win. The VirtIO drivers are reinstalled if the drivers in the guest tools ISO are newer than the ones previously installed from virtio-win. This ensures that the tools are kept up to date.