A Container Storage Interface (CSI) volume clone is a duplicate of an existing persistent volume at a particular point in time.
Volume cloning is similar to volume snapshots, although it is more efficient. For example, a cluster administrator can duplicate a cluster volume by creating another instance of the existing cluster volume.
Cloning creates an exact duplicate of the specified volume on the back-end device, rather than creating a new empty volume. After dynamic provisioning, you can use a volume clone just as you would use any standard volume.
No new API objects are required for cloning. The existing
dataSource field in the
PersistentVolumeClaim object is expanded so that it can accept the name of an existing PersistentVolumeClaim in the same namespace.
By default, OKD supports CSI volume cloning with these limitations:
The destination persistent volume claim (PVC) must exist in the same namespace as the source PVC.
The source and destination storage class must be the same.
Support is only available for CSI drivers. In-tree and FlexVolumes are not supported.
CSI drivers might not have implemented the volume cloning functionality. For details, see the CSI driver documentation.