Red Hat SummitCe contenu n'est pas disponible dans la langue sélectionnée.
Chapter 2. Release notes
2.1. Release notes
This release of the Windows Machine Config Operator (WMCO) provides bug fixes for running Windows compute nodes in an OpenShift Container Platform cluster.
2.1.1. Release notes for Red Hat Windows Machine Config Operator 10.20.0
Issued: 21 October 2025
The components of the Red Hat Windows Machine Config Operator (WMCO) 10.20.0 were released in RHBA-2025:18930.
2.1.1.1. New features and improvements
2.1.1.1.1. Kubernetes upgrade
The WMCO now uses Kubernetes version 1.33.
2.1.1.2. Bug fixes
- Previously, if you made a configuration change that required the WMCO to delete and recreate an internal config map, such as changing the proxy settings of the cluster, the WMCO pod panicked and entered a crash loop due to a nil pointer dereference panic. With this fix, the error handling logic is reworked. As a result, the WMCO pod no longer crashes when an internal config map is recreated. (OCPBUGS-60688)
- Previously, during secret reconciliations, secret change data was being added to the logs on each reconciliation loop. As a result, this secret change data was persisting, causing the logs to grow in size with unrelated data. With this fix, only the current secret change data is being logged, reducing the size and complexity of the logs. (OCPBUGS-61559)
-
Previously, the
hybridOverlayservice was not using the trusted CA bundle when connecting to Kubernetes, because thehybridOverlayservice command was missing the--k8s-cacertoption. Because of this, users could encounter trust issues or failures when thehybridOverlayservice attempted to communicate securely with Kubernetes clusters using custom or internal CAs. With this fix, thehybridOverlayservice command now includes the--k8s-cacert flagpointing to the trusted CA bundle. As a result, thehybridOverlayservice uses the trusted CA bundle for secure communication, preventing trust issues and ensuring compatibility with the cluster. - Previously, the WMCO neglected to close SSH connections when finishing node reconciliation. As a consequence, after adding a new Windows node to a cluster, the node SSH server eventually would refuse new connections due to being overwhelmed, causing node management issues. With this fix, the WMCO now properly closes SSH connections. As a result, the node SSH servers no longer refuse new connections due to this problem. (OCPBUGS-60482)
2.2. Windows Machine Config Operator prerequisites
The following information details the supported platform versions, Windows Server versions, and networking configurations for the Windows Machine Config Operator (WMCO). See the vSphere documentation for any information that is relevant to only that platform.
2.2.1. WMCO supported installation method
The WMCO fully supports installing Windows nodes into installer-provisioned infrastructure (IPI) clusters. This is the preferred OpenShift Container Platform installation method.
For user-provisioned infrastructure (UPI) clusters, the WMCO supports installing Windows nodes only into a UPI cluster installed with the platform: none field set in the install-config.yaml file (bare-metal or provider-agnostic) and only for the BYOH (Bring Your Own Host) use case. UPI is not supported for any other platform.
2.2.2. WMCO supported platforms and Windows Server versions
The following table lists the Windows Server versions that are supported by WMCO 10.20.0, based on the applicable platform. Windows Server versions not listed are not supported and attempting to use them will cause errors. To prevent these errors, use only an appropriate version for your platform.
| Platform | Supported Windows Server version |
|---|---|
| Amazon Web Services (AWS) |
|
| Microsoft Azure |
|
| VMware vSphere | Windows Server 2022, OS Build 20348.681 or later |
| Google Cloud | Windows Server 2022, OS Build 20348.681 or later |
| Nutanix | Windows Server 2022, OS Build 20348.681 or later |
| Bare metal or provider agnostic |
|
- For disconnected clusters, the Windows AMI must have the EC2LaunchV2 agent version 2.0.2107 or later installed. For more information, see the Install the latest version of EC2Launch v2 in the AWS documentation.
2.2.3. Supported networking
Hybrid networking with OVN-Kubernetes is the only supported networking configuration. See the additional resources below for more information on this functionality. The following tables outline the type of networking configuration and Windows Server versions to use based on your platform. You must specify the network configuration when you install the cluster.
- The WMCO does not support OVN-Kubernetes without hybrid networking or OpenShift SDN.
- Dual NIC is not supported on WMCO-managed Windows instances.
| Platform | Supported networking |
|---|---|
| Amazon Web Services (AWS) | Hybrid networking with OVN-Kubernetes |
| Microsoft Azure | Hybrid networking with OVN-Kubernetes |
| VMware vSphere | Hybrid networking with OVN-Kubernetes with a custom VXLAN port |
| Google Cloud | Hybrid networking with OVN-Kubernetes |
| Nutanix | Hybrid networking with OVN-Kubernetes |
| Bare metal or provider agnostic | Hybrid networking with OVN-Kubernetes |
2.3. Windows Machine Config Operator known limitations
Note the following limitations when working with Windows nodes managed by the WMCO (Windows nodes):
The following OpenShift Container Platform features are not supported on Windows nodes:
- Image builds
- OpenShift Pipelines
- OpenShift Service Mesh
- OpenShift monitoring of user-defined projects
- OpenShift Serverless
- Horizontal Pod Autoscaling
- Vertical Pod Autoscaling
- Hosted Control Planes
The following Red Hat features are not supported on Windows nodes:
- Dual NIC is not supported on WMCO-managed Windows instances.
- Windows nodes do not support workloads created by using deployment configs. You can use a deployment or other method to deploy workloads.
- Red Hat OpenShift support for Windows Containers does not support adding Windows nodes to a cluster through a trunk port. The only supported networking configuration for adding Windows nodes is through an access port that carries traffic for the VLAN.
- Red Hat OpenShift support for Windows Containers does not support any Windows operating system language other than English (United States).
-
Due to a limitation within the Windows operating system,
clusterNetworkCIDR addresses of class E, such as240.0.0.0, are not compatible with Windows nodes. Kubernetes has identified the following node feature limitations :
- Huge pages are not supported for Windows containers.
- Privileged containers are not supported for Windows containers.
- Kubernetes has identified several API compatibility issues.
'%20d='M201.5%20305.5c-13.8%200-24.9-11.1-24.9-24.6%200-13.8%2011.1-24.9%2024.9-24.9%2013.6%200%2024.6%2011.1%2024.6%2024.9%200%2013.6-11.1%2024.6-24.6%2024.6zM504%20256c0%20137-111%20248-248%20248S8%20393%208%20256%20119%208%20256%208s248%20111%20248%20248zm-132.3-41.2c-9.4%200-17.7%203.9-23.8%2010-22.4-15.5-52.6-25.5-86.1-26.6l17.4-78.3%2055.4%2012.5c0%2013.6%2011.1%2024.6%2024.6%2024.6%2013.8%200%2024.9-11.3%2024.9-24.9s-11.1-24.9-24.9-24.9c-9.7%200-18%205.8-22.1%2013.8l-61.2-13.6c-3-.8-6.1%201.4-6.9%204.4l-19.1%2086.4c-33.2%201.4-63.1%2011.3-85.5%2026.8-6.1-6.4-14.7-10.2-24.1-10.2-34.9%200-46.3%2046.9-14.4%2062.8-1.1%205-1.7%2010.2-1.7%2015.5%200%2052.6%2059.2%2095.2%20132%2095.2%2073.1%200%20132.3-42.6%20132.3-95.2%200-5.3-.6-10.8-1.9-15.8%2031.3-16%2019.8-62.5-14.9-62.5zM302.8%20331c-18.2%2018.2-76.1%2017.9-93.6%200-2.2-2.2-6.1-2.2-8.3%200-2.5%202.5-2.5%206.4%200%208.6%2022.8%2022.8%2087.3%2022.8%20110.2%200%202.5-2.2%202.5-6.1%200-8.6-2.2-2.2-6.1-2.2-8.3%200zm7.7-75c-13.6%200-24.6%2011.1-24.6%2024.9%200%2013.6%2011.1%2024.6%2024.6%2024.6%2013.8%200%2024.9-11.1%2024.9-24.6%200-13.8-11-24.9-24.9-24.9z'/%3e%3c/svg%3e){kind=small}