14    Snapshots

A snapshot is a point-in-time copy (image) of a container and all of its contents, including subcontainers and all data objects and queue objects. The client names a snapshot of a container at the time the snapshot is requested. A snapshot operation creates a new container to contain the point-in-time image. The first processing of a snapshot operation also adds a cdmi_snapshots child container to the Source Container. Each new snapshot container is added as a child of the cdmi_snapshots container. The snapshot does not include the cdmi_snapshots child container or its contents (see Figure 9).

SnapshotIllustrationNoShadow.jpg

 

Figure 9 - Snapshot Container Structure

A snapshot operation is requested using the container update operation (see 9.5), in which the snapshot field specifies the requested name of the snapshot.

A snapshot may be accessed in the same way that any other CDMI™ object is accessed. An important use of a snapshot is to allow the contents of the Source Container to be restored to their values at a previous point in time using a CDMI copy operation.