Alternate copy pools for system-level backups

In Db2 12, you can create extra system-level backups on alternate backup storage groups without affecting the primary system-level backup.

In previous releases, when you used the BACKUP SYSTEM utility to create system-level backups, you could use up to two copy pools only, one for the database and one for logs. These copy pools define the storage groups to copy and the backup storage groups to store the copies.

Beginning in Db2 12, you can also optionally use additional copy pools called alternate copy pools. An alternate copy pool includes the same defined set of storage groups as the standard copy pool; however different backup storage groups are specified. Therefore, you can make system-level backups on different target volumes. These target volumes can be shared among different Db2 subsystems. That is, a volume can be used by another subsystem if it is not part of an active copy. You can make these extra system-level backups without overwriting the primary production system-level backup or invalidating any versions in the regular backup storage group.

You can specify that you want to use an alternate copy pool when you make the system-level backup. To do so, specify the ALTERNATE_CP option and the related backup storage group options (DBBSG and LGBSG) on the BACKUP SYSTEM utility control statement.

Alternatively, you can specify that you want BACKUP SYSTEM to regularly alternate between using the standard copy pool and the alternate copy pool. For this behavior, use the ALTERNATE_CP subsystem parameter and the related backup storage group subsystem parameters (UTIL_DBBSG and UTIL_LGBSG).

The system-level backups that are made with the alternate copy pool can be used during recovery by the RESTORE SYSTEM utility or the RECOVER utility.