OpenShift docs are moving and will soon only be available at docs.redhat.com, the home of all Red Hat product documentation. Explore the new docs experience today.
  1. Documentation
    2. history
×

Virtual machine live migration

Prerequisites

  • Before using LiveMigration, ensure that the storage class used by the virtual machine has a PersistentVolumeClaim (PVC) with a shared ReadWriteMany (RWX) access mode. See Storage defaults for DataVolumes to ensure your storage settings are correct.

Understanding live migration

Live migration is the process of moving a running virtual machine instance to another node in the cluster without interrupting the virtual workload or access. This can be a manual process, if you select virtual machine instance to migrate to another node, or an automatic process, if the virtual machine instance has a LiveMigrate eviction strategy and the node on which it is running is placed into maintenance.

Virtual machines must have a PersistentVolumeClaim (PVC) with a shared ReadWriteMany (RWX) access mode to be live migrated.

Updating access mode for LiveMigration

For LiveMigration to function properly, you must use the ReadWriteMany (RWX) access mode. Use this procedure to update the access mode, if needed.

Procedure

  • To set the RWX access mode, run the following oc patch command:

    $ oc patch -n openshift-cnv \
    cm kubevirt-storage-class-defaults \
        -p '{"data":{"'$<STORAGE_CLASS>'.accessMode":"ReadWriteMany"}}'
Additional resources: