Snapshot function

Snapshots are the read only point-in-time copies of a volume group that cannot be directly accessible from the hosts. To access the snapshot contents, you can create a clone or thin clone of a volume group snapshot.

Using snapshot with FlashCopy

The snapshot function satisfies some of the use cases that are addressed by FlashCopy. Snapshots are a volume-centric approach that simplifies the overall management of point in time copies on the system. With snapshots, administrators can save a mutually consistent image of the volumes in the volume group or save a snapshot of an individual volume. The main use case of snapshot is corruption protection. It protects the user data from deliberate or accidental data corruption from the host's systems. Snapshot function can be used in parallel with the existing FlashCopy function; however, a snapshot is not compatible with FlashCopy function. When the volume has a snapshot, it cannot be part of any new FlashCopy mappings.

The snapshot function supports creating Safeguarded snapshots. Safeguarded snapshots are cyber-resilient copies and can be used for corruption protection and data recovery. Only users with Security Administrator access can delete these snapshots. An internal scheduler can be used to schedule Safeguarded snapshots by configuring a snapshot policy.

Snapshots are always in the same pool as the parent volume, or a child pool of this volume's parent pool if explicitly specified. The I/O group and preferred node are same as the parent volume when the snapshot was taken. Snapshot always inherits the set rules that are based on the type of parent pool. For example, if the parent pool is a standard pool, snapshots are always thin-provisioned with automatic expansion enabled.