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Use

This section describes how you can use BRBACKUP to perform a split-mirror online backup with your Oracle database. We especially recommend this for large databases where high availability is an important consideration.

In an online backup the system remains available the whole time. The tablespaces to be backed up are temporarily set to BACKUP status while the mirror disks are split. In comparison to the normal online backup, in which the tablespaces retain this status during the whole backup period, the amount of redo information is significantly reduced.

Prerequisites

You set the following parameters in the initialization profile init<DBSID>.sap:

Instead of the backup_type parameter, you can enter the BRBACKUP command option -t|-type as shown below in "Activities." The BRBACKUP command option takes priority.

Activities

You start BRBACKUP on the backup host using the following command :

brbackup -t online_split

For more information, see -t|-type.

BRBACKUP then performs the following steps:

  1. Sets the tablespaces to be backed up to BACKUP status using
    ALTER TABLESPACE <tablespace name> BEGIN BACKUP.
  2. Splits the mirror disks using split_cmd.
  3. Resets the tablespaces to the normal status using
    ALTER TABLESPACE <tablespace name> END BACKUP.
  4. Backs up the mirror disks.
  5. If you have set resync_cmd, synchronizes the mirror disks with the originals.

 

See also:

Split-Mirror Backup: Software Configuration

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