Chapter 12. Volume cloning

A clone is a duplicate of an existing storage volume that is used as any standard volume. You create a clone of a volume to make a point in time copy of the data. A persistent volume claim (PVC) cannot be cloned with a different size. You can create up to 512 clones per PVC for both CephFS and RADOS Block Device (RBD).

12.1. Creating a clone

Prerequisites

  • Source PVC must be in Bound state and must not be in use.
Note

Do not create a clone of a PVC if a Pod is using it. Doing so might cause data corruption because the PVC is not quiesced (paused).

Procedure

  1. Click StoragePersistent Volume Claims from the OpenShift Web Console.
  2. To create a clone, do one of the following:

    • Beside the desired PVC, click Action menu (⋮)Clone PVC.
    • Click on the PVC that you want to clone and click ActionsClone PVC.
  3. Enter a Name for the clone.
  4. Select the access mode of your choice.

    Important

    The ReadOnlyMany (ROX) access mode is a Developer Preview feature and is subject to Developer Preview support limitations. Developer Preview releases are not intended to be run in production environments and are not supported through the Red Hat Customer Portal case management system. If you need assistance with ReadOnlyMany feature, reach out to the ocs-devpreview@redhat.com mailing list and a member of the Red Hat Development Team will assist you as quickly as possible based on availability and work schedules. See Creating a clone or restoring a snapshot with the new readonly access mode to use the ROX access mode.

  5. Click Clone. You are redirected to the new PVC details page.
  6. Wait for the cloned PVC status to become Bound.

    The cloned PVC is now available to be consumed by the pods. This cloned PVC is independent of its dataSource PVC.