When a read request for a 3995 shelf-resident volume that belongs to a default pseudo library (with device type association) is received by OAM, any operator-accessible drive belonging to a pseudo library with an associated device type that is read-compatible with the volume is eligible to mount the volume.
When a read request for a 3995 shelf-resident volume that belongs to a pseudo library with no device type association is received, any operator-accessible drive (within the set of drives assigned to that pseudo library) with a device type that is read-compatible with the volume is eligible for the request.
If the request is a write request, drive selection is based on the drives in libraries associated with the storage group. A drive must belong to a library that is associated with the storage group in order to be considered. If a volume belonging to a pseudo library with a device type association is selected, only drives that are write-compatible and belong to a pseudo library that also has a device type association are eligible for the request. If the volume selected belongs to a pseudo library that has no device type association, then only drives that are write compatible with the selected volume and belong to the same pseudo library as the volume are eligible for the request. You can isolate volumes and operator-accessible drives by physical location instead of by device type. An installation can choose to have a large pseudo library if everything is in the same location, or have several pseudo libraries in various locations as long as there are associated drives that can satisfy the request.
When a shelf-resident optical volume is mounted on an operator-accessible drive in an OAMplex, the volume is managed and controlled by the instance of OAM to which the drive belongs. Any requests for the volume are then sent to the OAM where the volume is mounted, thus eliminating the need to demount and remount the volume.