Dell PowerVault MD 34XX/38XX Series Storage Arrays CLI Guide

A snapshot virtual disk is a point-in-time image of a virtual disk. It is typically created so that an application, such as a backup, can access the snapshot virtual disk and read the data while the source virtual disk remains online and accessible to hosts.

Creating a snapshot virtual disk automatically creates a snapshot repository virtual disk. The snapshot repository virtual disk stores information about the data that has changed since the snapshot virtual disk was created. Snapshot repository virtual disks cannot be selected as a source virtual disk or target virtual disk in a virtual disk copy.

The virtual disk for which the point-in-time image is created is the source virtual disk and must be a standard virtual disk in the storage array.

You can select snapshot virtual disks as the source virtual disk for a virtual disk copy. Selecting a snapshot virtual disk is a good use of this feature, because it enables complete backups without significant impact to the storage array I/O. However, some I/O processing resources are lost to the copy operation.

The Snapshot Virtual Disk feature can be used with the Virtual Disk Copy feature to back up data on the same storage array and to restore the data on the snapshot virtual disk back to its original source virtual disk.