Operations with shared libraries

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Shared libraries are logical libraries that are represented physically by SCSI libraries. The physical library is controlled by the IBM Storage Protect server that is configured as a library manager. IBM Storage Protect servers that use the SHARED library type are library clients to the IBM Storage Protect library manager server.

The library client contacts the library manager when the library manager starts and the storage device initializes, or after a library manager is defined to a library client. The library client confirms that the contacted server is the library manager for the named library device. The library client also compares drive definitions with the library manager for consistency. The library client contacts the library manager for each of the following operations:

Volume mount: A library client sends a request to the library manager for access to a particular volume in the shared library device. For a scratch volume, the library client does not specify a volume name. If the library manager cannot access the requested volume, or if scratch volumes are unavailable, the library manager denies the mount request. If the mount is successful, the library manager returns the name of the drive where the volume is mounted.
Volume release: When a library client no longer needs to access a volume, it notifies the library manager that the volume can be returned to a scratch volume. The library manager database is updated with the new location for the volume, which is now in the inventory of the library server. The volume is deleted from the volume inventory of the library client.

Table 1 shows the interaction between library clients and the library manager in processing IBM Storage Protect operations.

Table 1. How SAN-enabled servers process IBM Storage Protect operations
Operation (Command)	Library manager	Library client
Query library volumes (QUERY LIBVOLUME)	Displays the volumes that are checked into the library. For private volumes, the owner server is also displayed.	Not applicable.
Check in and check out library volumes (CHECKIN LIBVOLUME, CHECKOUT LIBVOLUME)	Sends the commands to the library device.	Not applicable. When a check-in operation is required because of a client restore operation, a request is sent to the library manager server.
Move media and move DRM media (MOVE MEDIA, MOVE DRMEDIA)	Valid only for volumes that are used by the library manager server.	Requests that the library manager server completes the operation. Generates a check-out process on the library manager server.
Audit library inventory (AUDIT LIBRARY)	Synchronizes the inventory with the library device.	Synchronizes the inventory with the library manager server.
Label a library volume (LABEL LIBVOLUME)	Labels and checks in volumes.	Not applicable.
Dismount a volume (DISMOUNT VOLUME)	Sends the request to the library device.	Requests that the library manager server completes the operation.
Query a volume (QUERY VOLUME)	Checks whether the volume is owned by the requesting library client and checks whether the volume is in the library device.	Requests that the library manager server completes the operation.