112 Using the Remote Replication Premium Feature
Snapshot Virtual Disks
A snapshot is a point-in-time image of a virtual disk. Typically, it is created so
that an application, such as a backup application, can access the snapshot
virtual disk and read the data while the base virtual disk stays online and is
accessible to hosts.
The virtual disk for which the point-in-time image is created is known as the
base virtual disk and must be a standard virtual disk in the storage array. The
snapshot repository virtual disk stores information about all data that
changed since the snapshot was created.
In this version of the MD storage management software, you can create
snapshot virtual disks based on the primary virtual disk or secondary virtual
disk of a remote replication.
Virtual Disk Copy
The Virtual Disk Copy premium feature copies data from one virtual disk
(the source virtual disk) to another virtual disk (the target virtual disk) within
a single storage array. You can use this premium feature to perform these
• Copy data from disk groups that use smaller-capacity physical disks to disk
groups that use larger-capacity physical disks
•Back up data
• Restore snapshot virtual disk data to the base virtual disk.
You can use a primary virtual disk in a remote replication as a source virtual
disk or a target virtual disk in a virtual disk copy. You cannot use a secondary
virtual disk as a source virtual disk or a target virtual disk.
NOTE: If you start a role reversal during a copy-in-progress, the copy fails and
cannot be restarted.
book.book Page 112 Wednesday, June 8, 2011 12:20 PM