70 Snapshot Virtual Diskssnapshot repository uses less disk space than a full physical copy, because theonly data blocks that are stored in the snapshot repository virtual disk arethose that have changed since the time of the snapshot.When you create a snapshot virtual disk, you specify where to create thesnapshot repository virtual disk, its capacity, and other parameters. You candisable or delete the snapshot virtual disk when you no longer need it, such aswhen the backup is complete. If you disable a snapshot virtual disk, you canre-create and reuse it the next time you perform a backup (see "Re-creatingSnapshot Virtual Disks" on page 82 for more information). If you delete asnapshot virtual disk, you also delete the associated snapshot repositoryvirtual disk.NOTE: Deleting a snapshot does not affect data on the source virtual disk.The information that follows will better prepare users for using the snapshotvirtual disk premium feature of the Dell PowerVault systems.NOTE: The following host preparation sections also apply when using the snapshotfeature through the CLI interface.Creating a Snapshot Virtual Disk Using theSimple PathYou can choose the simple path to create a snapshot virtual disk if the diskgroup of the source virtual disk has the required amount of free space. Asnapshot repository virtual disk requires a minimum 8 MB of free capacity.The destination of a snapshot repository virtual disk is determined based onthe free capacity available in the disk group.If 8 MB of free capacity is not available in the disk group of the source virtualdisk, the Create Snapshot Virtual Disks feature defaults to the advancedpath (see "Creating a Snapshot Virtual Disk Using the Advanced Path" onpage 75). In the advanced path option, you can choose to place the snapshotrepository virtual disk in another disk group or you can use unconfiguredcapacity on the storage array to create a new disk group.
