IBM Power Systems adds official support for Limited Live Migration from OpenShiftSDN to OVN-Kubernetes. Administrators are able to migrate off OpenShiftSDN cluster networks to OVN-Kubernetes without experiencing service interruption. As the preferred migration path, it ensures that enterprise workloads running on OpenShift COntainer Platform on IBM Power maintain continuous availability. For environments where a live transition is not feasible, IBM Power also supports the offline migration method to ensure a successful network evolution.

Steps

1. Verifying Setup a. Ensure you are the latest eus-4.16 which is 4.16.54. We used this when testing. OpenShift Upgrade Path b. Ensure the oc get co returns all Operators Ready and none are degrated. c. Review Diagnostic Steps in the Knowledge Base Article: Limited Live Migration from OpenShift SDN to OVN-Kubernetes https://access.redhat.com/solutions/7057169

2. If everything is OK, you can initiate the limited live migration per 19.5.1.5.4. Initiating the limited live migration process

oc patch Network.config.openshift.io cluster --type='merge' --patch '{"metadata":{"annotations":{"network.openshift.io/network-type-migration":""}},"spec":{"networkType":"OVNKubernetes"}}'

3. Watch the network.config to see it is complete.

oc patch Network.config.openshift.io cluster --type='merge' --patch '{"metadata":{"annotations":{"network.openshift.io/network-type-migration":""}},"spec":{"networkType":"OVNKubernetes"}}'

4. After a successful migration operation, remove the network.openshift.io/network-type-migration- annotation from the network.config custom resource by entering the following command:

oc annotate network.config cluster network.openshift.io/network-type-migration-

5. Afterwards, you may see the following output in network.config, this is OK, and expected.

  # oc get network.config -oyaml
  apiVersion: config.openshift.io/v1
  kind: Network
  metadata:
    creationTimestamp: "2025-12-09T07:03:09Z"
    generation: 18
    name: cluster
    resourceVersion: "545748"
    uid: b3ec83d9-f1ba-4a44-959a-0c60f3e19866
  spec:
    clusterNetwork:
    - cidr: 10.128.0.0/14
      hostPrefix: 23
    externalIP:
      policy: {}
    networkType: OVNKubernetes
    serviceNetwork:
    - 172.30.0.0/16
  status:
    clusterNetwork:
    - cidr: 10.128.0.0/14
      hostPrefix: 23
    clusterNetworkMTU: 1350
    conditions:
    - lastTransitionTime: "2025-12-10T07:25:55Z"
      message: ""
      reason: AsExpected
      status: "True"
      type: NetworkDiagnosticsAvailable
    - lastTransitionTime: "2025-12-10T07:41:38Z"
      message: Network type migration is not in progress
      reason: NetworkTypeMigrationNotInProgress
      status: Unknown
      type: NetworkTypeMigrationMTUReady
    - lastTransitionTime: "2025-12-10T07:41:38Z"
      message: Network type migration is not in progress
      reason: NetworkTypeMigrationNotInProgress
      status: Unknown
      type: NetworkTypeMigrationTargetCNIAvailable
    - lastTransitionTime: "2025-12-10T07:41:38Z"
      message: Network type migration is not in progress
      reason: NetworkTypeMigrationNotInProgress
      status: Unknown
      type: NetworkTypeMigrationTargetCNIInUse
    - lastTransitionTime: "2025-12-10T07:41:38Z"
      message: Network type migration is not in progress
      reason: NetworkTypeMigrationNotInProgress
      status: Unknown
      type: NetworkTypeMigrationOriginalCNIPurged
    - lastTransitionTime: "2025-12-10T07:41:38Z"
      message: Network type migration is completed
      reason: NetworkTypeMigrationCompleted
      status: "False"
      type: NetworkTypeMigrationInProgress
    networkType: OVNKubernetes
    serviceNetwork:
    - 172.30.0.0/16

Best wishes with your migration.

Reference

1. 19.5.1.1. Supported platforms when using the limited live migration method https://docs.redhat.com/en/documentation/openshift_container_platform/4.16/html/networking/ovn-kubernetes-network-plugin#supported-platforms-live-migrating-ovn-kubernetes
2. Also posted to https://bastide.org/2026/01/06/ibm-power-adds-limited-live-migration-support-to-openshift-4-16/