A Snapshot copy is a point-in-time, real-time, online, and read-only copy of a LUN stored on a volume. SnapManager Backup uses the Snapshot technology to create copies of Exchange databases that reside in these LUNs.
Data ONTAP software allows a maximum of 255 Snapshot copies per volume. To avoid reaching the limit, delete old SnapManager backups that are no longer needed. Do this because SnapManager backups automatically create Snapshot copies.
Note: The number of Snapshot copies on a volume can be greater than the number of SnapManager backups being retained. For example, if a single volume contains both the SnapInfo directory and the Exchange databases, each SnapManager backup generates two Snapshot copies on that volume. Therefore the number of Snapshot copies is double the number of backups on the same volume.
For more information about Snapshot technology, see the Data ONTAP Storage Management Guide.