Clones (physical copies)

HPE SSMC allows you to create point-in-time clones (physical copies) of virtual volumes. When the Create Clone action starts, a point-in-time snapshot is instantly created of the parent virtual volume. Then all of the data is physically copied to the target virtual volume. If you choose to retain the point-in-time snapshot, the relationship between the clone and its parent virtual volume is retained, which allows you to later resynchronize the clone with the parent.

  • Prior to creating a clone virtual volume, you must create an unexported virtual volume with the characteristics that you want for the clone. The Create Clone dialog ensures that only appropriate virtual volumes are available for selection as a target.

  • An option in the Create Clone dialog allows the point-in-time snapshot to be saved, or not saved. If the snapshot is saved, the target virtual volume becomes a clone that can be resynchronized later with the parent. If the snapshot is not saved, the data is copied from the parent to the target virtual volume, but the target does not become a clone. Rather, the target remains a base virtual volume and cannot be resynchronized with the parent.

  • Copying data from a large parent virtual volume can take several minutes to hours. Until the copy process is complete, the clone virtual volume cannot be exported to a host.

  • If necessary, you can stop the cloning process while it is running. If you stop the cloning process, the target virtual volume reverts to being a base virtual volume and will contain incomplete data.

Resynchronization

Resynchronization updates data on a clone with newer point-in-time data from the parent virtual volume. The HPE Storage OS takes a new snapshot of the parent and uses the new and old snapshots to update the clone. By default, the old snapshot is deleted and the new snapshot is retained for later resynchronization.

Learn more: Resynchronizing clones.

Promotion

The Promote clone action changes a virtual volume from a clone to a base virtual volume. Promotion removes the association between the clone and the parent virtual volume.

Clone snapshots

The snapshots (virtual volumes) that are created automatically for clones have file names that begin with the letters vvcp, for example vvcp.667.588.