SnapManager requires that all databases be mounted before verification. The SnapManager verification server must have enough drive letters or mountpoints to mount the LUNs that store the backup sets that you verify, depending on your verification scenario.
SnapManager mounts the LUNs that contain the backup sets that you select for verification with SnapDrive commands. Each mounted LUN requires one available drive letter or mountpoint.
To verify backups that are stored on a single LUN or across multiple LUNS, the verification server must have at least one drive letter or mountpoint available.
If you are using a remote verification server, you need two unassigned drive letters or mountpoints to verify multiple backup sets in a single job.
In other situations, you need one unassigned drive letter or mountpoint.
The one unassigned drive letter or mountpoint is to mount the LUN in a Snapshot copy. The Snapshot copy stores the transaction log directory for multiple Storage Groups for transaction log verification. When SnapManager verifies the transaction logs for the first backup set, it does not unmount the LUN or release the assigned drive letter. SnapManager reuses the same LUN for the transaction log verification for the second backup set.