Shared Storage Option management process
Shared Storage Option (SSO) is an extension to tape drive allocation and configuration for media and device management. SSO allows individual tape drives (standalone or in a robotic library) to be dynamically shared between multiple NetBackup media servers or SAN media servers.
For more information about the Shared Storage Option, see the NetBackup Administrator's Guide, Volume II.
The following shows the Shared Storage Option management process in the order presented:
NetBackup or users can initiate backups. The nbjm process makes a mount request for the backup.
nbrb tells the EMM server to obtain a drive for the backup.
nbrb tells the device allocator (DA) in the EMM server to stop scanning the selected drive.
nbemm tells the appropriate media server (the scan host for the selected drive) to stop scanning the drive. The stop scan request is carried out by means of oprd, ltid, and avrd in the media server's shared memory.
nbemm informs nbrb when the scanning on the selected drive has stopped.
nbrb informs nbjm that the selected drive (A) is available for the backup.
nbjm conveys the mount request and drive selection to bptm, which proceeds with the backup. To protect the integrity of the write operation, bptm uses SCSI reservations.
For more information about how NetBackup reserves drives, see the NetBackup Administrator's Guide, Volume II.
The mount-media operation is initiated.
bptm makes position checks on the drive to ensure that another application has not rewound the drive. bptm also does the actual write to the tape.
When the backup is complete, nbjm tells nbrb to release resources.
nbrb de-allocates the drive in EMM.
EMM tells the scan host to resume scanning the drive. The scan request is carried out by means of oprd, ltid, and avrd in the media server's shared memory.
Figure: Media and device management process flow showing SSO components illustrates the Shared Storage Option management process.
