Automatic Volume Management 

Purpose

BRBACKUP/BRARCHIVE automatically select the volumes that are recommended for the next backup. The name of the mounted volume is compared to the name found in the volume pool. In addition, the procedure ensures that current backups are not overwritten.

Prerequisites

When you use automatic volume management, do not use weekdays or days of the month in the volume names, because BRBACKUP/BRARCHIVE do not check whether a holiday fell in the period since the last backup or not. SAP recommends that you include the name of the database instance and a sequential number in the tape name, for example <DBSID>A<nn> for BRARCHIVE tapes, <DBSID>B<nn> for BRBACKUP tapes.

Procedure

  1. Define a pool of the volumes available for the backup. To do this, enter the corresponding volume names in profile parameter volume_backup or volume_archive . All the volumes defined there should physically exist; initialize new volumes when necessary.
  2. Determine whether the required expiration period has been configured in profile parameter expir_period ; change the value when necessary.
  3. Start the backup with BRBACKUP or BRARCHIVE. Only volumes that are not locked are selected from the pool of available volumes. Mount the requested volumes. During the next program run, BRBACKUP and BRARCHIVE will attempt to write to all the available volumes in the pool in sequence.

Activities

The names of the volumes that will be required for the next volume can be displayed as follows:

brbackup/brarchive -q

You can check whether you have mounted the right volume in the backup device:

brbackup/brarchive -q check

Neither call actually starts the backup. In particular, you should use these options before scheduling a backup with CRON or a similar utility.

See -q|-query

If you want to select the volumes manually you can deactivate automatic tape management: Set the init<DBSID>.sap parameters volume_backup and volume_archive to SCRATCH or call BRBACKUP/BRARCHIVE with the option -v SCRATCH .