HP 418800-B21 HP StorageWorks Replication Solutions Manager 4.0.1 user guide ( - Page 441

• Can I create a snapshot of a snapclone? Yes. • Can I create an snapshot of a snapshot? No. Snapshot guidelines The following guidelines apply to snapshot virtual disks: • The array must have a local replication license. See replication licenses overview. • The maximum number of snapshots per source varies with controller software versions. See controller software features - local replication. • A snapshot is always created in the same disk group as the source virtual disk. • The redundancy level (Vraid) of a snapshot must be the same or lower than the source. See redundancy level (Vraid). • All snapshots of the same virtual disk must be the same type (demand allocated or fully allocated) and redundancy level. See snapshot types (allocation policy). • Demand-allocated snapshots can run out of space if the disk group has insufficient space for the snapshots to grow. In this event, the array stops writing to both the source and the snapshots. • Snapshots count against the maximum number of virtual disks per array. Snapshots cannot be created when the disk to be replicated is: • A snapshot • In the process of normalizing or being deleted. See normalization. Snapshots per virtual disk In HP XCS controller software, the maximum number of snapshots per virtual disk varies with the size of the disk. This is because the total snapshot size (per disk) cannot exceed 15 TB. Virtual disk snapshot estimator Source size (TB) Snapshots (max) 0 < to 0.94 16 0.95 to 1.00 15 1.01 to 1.07 14 1.08 to 1.15 13 1.16 to 1.25 12 1.26 to 1.36 11 1.37 to 1.50 10 1.51 to 1.67 9 1.68 to 1.88 8 1.89 to 2.00 7 The maximum size of a virtual disk is 2 TB. Snapshot types (allocation policy) Snapshot types (allocation policy) specifies how the storage system allocates space in a disk group for a snapshot. Values are: HP StorageWorks Replication Solutions Manager 4.0.1 441