The PVL manages all HPSS physical volumes. Clients can ask the PVL to mount and dismount sets of physical volumes.
Clients can also query the status and characteristics of physical volumes.
The PVL also controls all allocation of drives. When the PVL accepts client requests for volume mounts, the PVL allocates resources to satisfy the request. The client is notified when the mount has completed. The volume mount service is provided to clients such as a storage server. Multiple volumes may be specified as part of a single request.