Important note on VSS and disk arrays
To back up a Windows client with the VSS method, please note the following about snapshot parameter values:
For Provider Type of 3-hardware and Snapshot Attribute of 2-plex, you must configure an appropriate number of clones or mirrors in the disk array.
You must also synchronize the clones or mirrors with the disk array source device before starting the backup. If the clones or mirrors are not synchronized before the backup begins, VSS cannot select a clone or mirror on which to create the snapshot. As a result, the backup fails.