About Exchange Instant Recovery with the Microsoft VSS Provider
A special requirement exists when you want to use Instant Recovery with the Microsoft VSS Provider. Veritas recommends when you create a policy for an Exchange standalone server that you include only the databases that are on a common volume.
If an IR policy backs up databases on multiple volumes and you restore a subset of those volumes, NetBackup deletes the other snapshots. Otherwise the backup image contains an incomplete snapshot set. A rollback with the Microsoft VSS Provider consumes the snapshot because it does not provide for re-snapping the volume.
If you use Instant Recovery with the Microsoft VSS Provider and you select any items that span multiple volumes, the following occurs:
NetBackup creates a backup set with one snapshot for each volume.
During restores, if any snapshots are rolled back, all of the snapshots in that set are deleted. (With the SFW VSS provider or the hardware system provider, the rolled back snapshots are re-snapped so that the snapshot set remains complete.)
This situation is a limitation of the Microsoft VSS Provider. It typically occurs when you do a roll-forward restore of a database and log folders that are on separate volumes. The database volume normally is rolled back but the log volume is copied back. This action preserves the logs that were created since the backup. NetBackup then deletes the log snapshot and removes the IR copy of the backup image from the catalog. If a storage unit copy of the backup exists, it remains.