This parameter is used by BRBACKUP to identify the volume set to be used for the backup of the database or non-database files.
Syntax: volume_backup = <vol>|<vol_list>
The length of the volume name is limited to 10 characters.
Required values: Names of volumes that are to be used for database or other backups. If you specify more than one volume, you must separate the names with commas and enclose the list in parentheses. You can also enter SCRATCH to deactivate automatic volume management.
When BRBACKUP is started, the automatic volume management checks all the volumes in the sequence of their names in volume_backup (only volumes whose expiration period has expired are suggested for backup). The volumes are suggested cyclically.
You have two backup devices available, and three valid volumes were found in parameter volume_backup (the expiration period for these volumes has expired). The program assumes that you have mounted two of the selected volumes in the devices. If a third volume is required to complete the backup, the program prompts you to mount the third selected volume at the appropriate time.
The expiration period can be configured using parameter expir_period. The automatic volume management ensures that only free volumes are offered for backup, for example, those whose expiration period has expired. As a result, you have to supply a quantity of volumes that is large enough for your selected expiration period.
You perform a backup once a day, two volumes (tapes) are required; parameter expir_period is set to 14 (each volume is locked for 14 days at a time). In this case, you must specify at least 28 volumes to ensure that a volume is always available. Even better is to add a buffer of around 25%, for example, specifying 35 or more volumes in this case.
To deactivate the automatic volume management, use the command volume_backup = SCRATCH. In this case, you can mount any volume whose expiration period has expired. This name is then also recorded during the backup.