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. Supported cluster versions for OpenShift Virtualization OpenShift Virtualization 4.18 is supported for use on OpenShift Container Platform 4.18 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. Virtualization You can now change the instance type associated with a running virtual machine (VM) without restarting the VM. This feature was previously Technology Preview and is now generally available. You can now export VMs that have a virtual Trusted Platform Module (vTPM) device added to them, create snapshots of these VMs, and restore the VMs from snapshots. Note that cloning a VM with a vTPM device attached to it or creating a new VM from its snapshot is not supported. With the addition of the ReadWriteOnce (RWO) Filesystem support, you can now use any storage class for disks that persist the VM state such as vTPM or EFI. Previously, the storage class had to be of type Filesystem with the ReadWriteMany (RWX) access mode to persist across VM reboots. 2.1.4.2. Networking You can now connect a VM to a user-defined network (UDN) on the primary interface of the VM. You can now use primary user-defined networks for VMs on a public cloud. 2.1.4.3. Web console You can now increase the size of the persistent volume claim (PVC) of a VM disk in the web console without leaving the VirtualMachines page and with the VM running. You can now control the state of multiple virtual machines from the OpenShift Container Platform web console. As a cluster administrator, you can view the state of the node network of the cluster (NNS) in the form of a topology diagram . The NNS topology diagram displays all node components (network interface controllers, bridges, bonds, and VLANs), their properties and configurations, and connections between the nodes. You can open the topology diagram from the NodeNetworkState page of the web console. 2.1.4.4. Monitoring You can now view virtual machine (VM) workload metrics for allocated storage, CPU, and network resources. Admins can use these metrics to determine resource allocation and capacity planning. For a complete list of virtualization metrics, see KubeVirt components metrics . 2.1.4.5. Documentation improvements You can now find information about virtual machines in 3 new sections in the OpenShift Virtualization documentation: Creating a virtual machine documents basic VM creation. Advanced VM creation documents advanced ways to create VMs. Managing VMs documents all procedures relevant to managing VMs, both basic and advanced. These sections include streamlined and improved content. 2.1.4.6. Notable technical changes Changing the default storage class automatically deletes and re-imports existing boot sources. If boot source images were stored as volume snapshots and no default storage class is set, the snapshots are cleaned up and new data volumes are created but will not import until a default storage class is configured. 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 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 no longer supported in OpenShift Virtualization. The tekton-tasks-operator` is removed. The Tekton tasks and example pipelines are now available in the task catalog (ArtifactHub). 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 use OpenShift Virtualization on an OpenShift Container Platform cluster that has been deployed in a logical partition (LPAR) on IBM Z(R) and IBM(R) LinuxONE (s390x architecture) systems. For more information, see IBM Z and IBM LinuxONE compatibility . You can now use the OpenShift Container Platform web console to migrate one or more disks attached to a virtual machine (VM) to a different storage class . For the storage class migration to be successful, the VM must be running and the cluster must have a node available for live migration of the VM. 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 VM storage live migration in OpenShift Virtualization in the Red Hat knowledge base. 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. If you perform storage class migration for a stopped VM, the VM might not be able to start because of a missing bootable device. To prevent this, do not attempt storage class migration if the VM is not running. ( CNV-55104 ) Important Storage class migration 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 . Virtualization Virtual machine instance migrations might fail during workload updates or when a large number of migrations are triggered. This is more likely to occur if there are at least 400 pending migrations, undefined migrations, or a combination of both. ( CNV-56659 ) As a workaround, follow the procedure in the Red Hat Knowledgebase solution for this issue . 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 ) IBM Z and IBM LinuxONE Important Using OpenShift Virtualization with s390x architecture 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 . When you create a VM by using Red Hat Enterprise Linux (RHEL) container disk images for s390x architecture, call traces referencing virtio_balloon print to the VM console. ( OCPBUGS-51113 ) As a workaround, add the following parameter to the VM YAML configuration: spec.autoattachMemBalloon: false . In the web console, the Boot mode list for an s390x VM incorrectly includes BIOS , UEFI , and UEFI (secure) boot modes. If you select one of these modes for an s390x-based VM, the operation fails. This is because VMs based on s390x architecture can only use the IPL boot mode. ( CNV-56889 ) In the web console, it is erroneously possible to define multiple CPU threads for a VM based on s390x architecture. If you define multiple CPU threads, the VM enters a CrashLoopBackOff state with the error qemu-kvm: S390 does not support more than 1 threads . ( CNV-56890 )

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