Chapter 2. Release notes

2.1. OpenShift Virtualization release notes

2.1.1. Providing documentation feedback

To report an error or to improve our documentation, log in to your Red Hat Jira account and submit a Jira issue.

2.1.2. About Red Hat OpenShift Virtualization

With Red Hat OpenShift Virtualization, you can bring traditional virtual machines (VMs) into OpenShift Container Platform and run them alongside containers. In OpenShift Virtualization, VMs are native Kubernetes objects that you can manage by using the OpenShift Container Platform web console or the command line.

OpenShift Virtualization is represented by the icon.

You can use OpenShift Virtualization the OVN-Kubernetes Container Network Interface (CNI) network provider.

Learn more about what you can do with OpenShift Virtualization.

Learn more about OpenShift Virtualization architecture and deployments.

Prepare your cluster for OpenShift Virtualization.

2.1.2.1. OpenShift Virtualization supported cluster version

OpenShift Virtualization 4.17 is supported for use on OpenShift Container Platform 4.17 clusters. To use the latest z-stream release of OpenShift Virtualization, you must first upgrade to the latest version of OpenShift Container Platform.

2.1.2.2. Supported guest operating systems

To view the supported guest operating systems for OpenShift Virtualization, see Certified Guest Operating Systems in Red Hat OpenStack Platform, Red Hat Virtualization, OpenShift Virtualization and Red Hat Enterprise Linux with KVM.

2.1.2.3. Microsoft Windows SVVP certification

OpenShift Virtualization is certified in Microsoft’s Windows Server Virtualization Validation Program (SVVP) to run Windows Server workloads.

The SVVP certification applies to:

Red Hat Enterprise Linux CoreOS workers. In the Microsoft SVVP Catalog, they are named Red Hat OpenShift Container Platform 4 on RHEL CoreOS 9.
Intel and AMD CPUs.

2.1.3. Quick starts

Quick start tours are available for several OpenShift Virtualization features. To view the tours, click the Help icon ? in the menu bar on the header of the OpenShift Container Platform web console and then select Quick Starts. You can filter the available tours by entering the keyword virtualization in the Filter field.

2.1.4. New and changed features

This release adds new features and enhancements related to the following components and concepts:

2.1.4.1. Infrastructure

Configuring VM eviction strategies for an entire cluster is now generally available.

The inferFromVolume attribute is now supported for use with imported container disks. When requested, OpenShift Virtualization can copy the labels instancetype.kubevirt.io/default-instancetype and instancetype.kubevirt.io/default-preference from a source container disk to the boot volume of a new VM.

You can now select a custom namespace for Red Hat golden images instead of using the default openshift-virtualization-os-images namespace. By using a custom namespace, cluster administrators can restrict user access to the default boot sources. To update this setting by using the web console, go to Virtualization Overview Settings Cluster General settings Bootable volumes project.

2.1.4.2. Virtualization

You can now increase VM workload density on nodes by overcommitting memory (RAM) with the wasp-agent. The wasp agent assigns swap resources to worker nodes and manages pod evictions when nodes are at risk.
Note
Overcommitting memory on a highly utilized system can decrease workload performance.
Enabling post-copy live migration for VM workloads is now generally available.

As a cluster administrator, you can expose USB devices in a cluster, making them available for virtual machine (VM) owners to assign to VMs. You expose a USB device by first enabling host passthrough and then configuring the VM to access the USB device.

You can now use the Application-Aware Quota (AAQ) Operator to customize and manage resource quotas for individual components in an OpenShift Container Platform cluster. The AAQ Operator provides the ApplicationAwareResourceQuota and ApplicationAwareClusterResourceQuota custom resource definitions (CRDs) that can be used to allocate resources without interfering with cluster-level activities such as upgrades and node maintenance.

OpenShift Virtualization release 4.17.1 introduces support for Microsoft Windows Server 2025 as a certified guest operating system. See Certified Guest Operating Systems in OpenShift Virtualization for more details.

2.1.4.3. Storage

The VirtualMachineSnapshot API version is now v1beta1.

The VirtualMachineExport API version is now v1beta1.

2.1.4.4. Web console

The OpenShift Container Platform web console includes a new focused view, which presents a condensed navigation menu specific to the OpenShift Virtualization perspective. This view complements but does not replace the existing OpenShift Container Platform web console Virtualization navigation options.
To access the new view, navigate to Administrator Virtualization in the web console.
An OpenShift Virtualization guided tour is now available. You can access the tour by either clicking Start Tour on the Welcome to OpenShift Virtualization dialog or navigating to Virtualization Overview Settings User Getting started resources Guided tour.
Hot plugging memory for VMs from the web console is now generally available.
Hot plugging CPUs for VMs from the web console is now generally available.

2.1.5. Deprecated and removed features

2.1.5.1. Deprecated features

Deprecated features are included in the current release and supported. However, they will be removed in a future release and are not recommended for new deployments.

The DevPreviewLongLifecycle profile is deprecated. The profile is now LongLifecycle and is generally available.

The tekton-tasks-operator is deprecated and Tekton tasks and example pipelines are now deployed by the ssp-operator.

The copy-template, modify-vm-template, and create-vm-from-template tasks are deprecated.

Support for Windows Server 2012 R2 templates is deprecated.

The alerts KubeVirtComponentExceedsRequestedMemory and KubeVirtComponentExceedsRequestedCPU are deprecated. You can safely silence them.

2.1.5.2. Removed features

Removed features are those that were deprecated in earlier releases. They are now removed from OpenShift Virtualization and are no longer supported.

No features were removed in this release.

2.1.6. Technology Preview features

Some features in this release are currently in Technology Preview. These experimental features are not intended for production use. Note the following scope of support on the Red Hat Customer Portal for these features:

Technology Preview Features Support Scope

You can now migrate storage classes for running and stopped VMs.
Note
Storage live migration is not enabled by default in the HyperConverged custom resource. To enable the required feature gates, follow the workaround documented in Enable storage live migration in OpenShift Virtualization 4.17 in the Red Hat knowledge base.

You can now enable nested virtualization on OpenShift Virtualization hosts.

2.1.7. Known issues

Nodes

Uninstalling OpenShift Virtualization does not remove the feature.node.kubevirt.io node labels created by OpenShift Virtualization. You must remove the labels manually. (CNV-38543)

In a heterogeneous cluster with different compute nodes, virtual machines that have HyperV reenlightenment enabled cannot be scheduled on nodes that do not support timestamp-counter scaling (TSC) or have the appropriate TSC frequency. (BZ#2151169)

Storage

If you clone more than 100 VMs using the csi-clone cloning strategy, then the Ceph CSI might not purge the clones. Manually deleting the clones might also fail. (CNV-23501)
- As a workaround, you can restart the ceph-mgr to purge the VM clones.

Virtualization

When adding a virtual Trusted Platform Module (vTPM) device to a Windows VM, the BitLocker Drive Encryption system check passes even if the vTPM device is not persistent. This is because a vTPM device that is not persistent stores and recovers encryption keys using ephemeral storage for the lifetime of the virt-launcher pod. When the VM migrates or is shut down and restarts, the vTPM data is lost. (CNV-36448)

OpenShift Virtualization links a service account token in use by a pod to that specific pod. OpenShift Virtualization implements a service account volume by creating a disk image that contains a token. If you migrate a VM, then the service account volume becomes invalid. (CNV-33835)
- As a workaround, use user accounts rather than service accounts because user account tokens are not bound to a specific pod.

Web console

When you create a persistent volume claim (PVC) by selecting With Data upload form from the Create PersistentVolumeClaim list in the web console, uploading data to the PVC by using the Upload Data field fails. (CNV-37607)