Home > Storage > PowerMax and VMAX > Data Protection > Dell EMC PowerMax and VMAX All Flash: Snapshot Policies > Setting a policy snapshot to persistent
When a policy snapshot is in a persistent state, it cannot be recycled when the retention time or maximum snapshot count is reached. This attribute is useful when a specific point-in-time image is needed for longer than the typical timeframe for the respective snapshot policy. Only existing policy snapshots can be set to persistent. There is no option to create snapshots with the persistent setting, and manual snapshots cannot be set to persistent. The following figure shows how to set a policy snapshot to persistent.
The following figure shows a policy snapshot that has been set to persistent.
After setting a snapshot to persistent, the policy continues to take regularly scheduled snapshots and maintain compliance. When a persistent snapshot passes the point when it would be recycled, the maximum count of the policy may be exceeded.
In one example, persistence is set on the newest snapshot of a running policy that calls for one snapshot per day with a maximum of 10 snapshots. Over the next 10 days, the application always has 10 snapshots of this policy. After day 10, and until persistence is removed from the snapshot, there is a total 11 snapshots created by the policy.
This behavior guarantees the application always has snapshots of the required intervals. However, users must be aware of the potential increase in resource usage.
Note: A persistent policy snapshot can be terminated manually without removing the persistent setting. The persistent setting only prevents the policy from recycling the snapshot.