Release Notes

7 Dell PS Series: Space Borrowing for Snapshots and Replicas | TR1084 | version 2
1.1.1.1 Snapshot reserve settings
Depending on the number of snapshots and the amount of changes made to the base volume, snapshot reserve can
become entirely consumed. If this happens, the default action is to delete the oldest snapshot, providing the necessary
free space to create a new snapshot. However, there are various other configurable defaults for snapshot space.
Default Snapshot reserve settings can be managed at the PS Series group level, and at the individual volume level.
Note: Modifying default Snapshot space settings at the group level affects subsequently created volumes, not existing
volumes.
To modify the default Snapshot policy for the entire PS Series group:
1. In Group Manager, select the group in the left pane.
2. Click Group Configuration.
3. Click the Defaults tab.
Snapshot space reserve settings use group default values, unless you explicitly change them for an individual volume.
Table 1 Snapshot reserve settings
Item
Description
Snapshot space reserve
Amount of snapshot storage space, based on a percentage of the volume,
reserved in the local storage pool. If the size of a volume changes, the amount
of snapshot reserve also changes.
Warn when in-use space
reaches this percentage of
snapshot reserve
Percentage of the snapshot reserve, when reached by in-use snapshot reserve,
results in an event message. The default is 90 percent of the snapshot reserve.
Snapshot space recovery
policy
• Set the volume (and snapshots) offline
• Delete the oldest snapshots to free space for new snapshots
• Borrow snapshot space as needed
To modify the Snapshot policy for an individual volume:
4. In Group Manager, click the group in the left pane.