Parallel Backup of Large Databases to Disk with BRBACKUP


You can use BRBACKUP to back up your large Oracle database to multiple disks in parallel.


You must define the directories with the backup_root_dir parameter.


?      You can perform the backup with or without software compression.

?      You can control the degree of parallelism – that is, the number of parallel copy processes – using the exec_parallel parameter or the BRBACKUP command option -e|-execute.

?      If required, you can make a two-phase backup, that is, first to disk and then to tape.


To avoid imposing extra processing load on the database server during the second phase of a two-phase backup, consider the following procedure instead:


       1.      Unmount the file system from the database server.

       2.      Mount the file system on a second host.

       3.      Start the backup from this host.

A requirement for this procedure is that the hard-disk controllers for the backup disks can be physically mounted on both hosts simultaneously. The unmount and mount operations – that is, umount and mount – are necessary, since the file system cannot be mounted on different computers at the same time due to the buffering mechanism.

Alternatively, you can back up directly to remote disks. This eliminates the need for umountand mount.

Another approach to reduce processing load on the production database host is to use split mirror backup.