Dell TimeFinder SnapVX provides space-saving and efficient local replication in PowerMax arrays. SnapVX snapshots are a pointer-based structure that preserves a point-in-time view of a source volume. Snapshots provide the ability to manage consistent point-in-time copies for storage groups and are created with a user-defined name and optional expiration date (time-to-live), and without the use of a target volume. Host-accessible target volumes can be linked if a point-in-time snapshot needs to be accessed. Writing to a linked target does not affect the point-in-time of the snapshot.
SnapVX snapshots can be set as secure snaps. Secure snaps are snapshots that cannot be deleted, accidentally or intentionally. They are retained in resource-limited situations in which conventional snapshots are placed in a failed state to release resources.
Secure snaps must be created with a time-to-live retention period. The snapshot cannot be terminated before the retention time, and all termination attempts are rejected. When the retention time is reached, the snapshot is terminated.
The retention period on a secure snap can be extended in situations where the snapshot is needed longer than originally planned; however, reducing the retention time is not allowed. A traditional snapshot can be converted to a secure snap, but a secure snap cannot be converted to a traditional snapshot. All other SnapVX operations and rules apply to secure snaps.
When implementing secure snaps, a user should determine how many snapshots on an array must be secure. Users should consider using secure snaps only on certain critical volumes, or only on a subset of the snapshots to capture points-in-time that are critical to the business and for how long the secure snaps should be retained. As always, proper planning and system sizing is crucial, no matter the types or number of snapshots that will exist in an environment.
The following figure shows an example of creating secure snaps with a retention time of five days.