Configuring Backup Duplexing: CONFIGURE... BACKUP COPIES

Use the CONFIGURE ... BACKUP COPIES command to specify how many copies of each backup piece should be created on the specified device type for the specified type of file. This feature is known as duplexing. The CONFIGURE setting s for duplexing only affect backups of datafiles, control files and archived logs into backup sets, and do not affect image copies.

Note:

Control file autobackups on disk are a special case and are never duplexed: RMAN always creates one and only one copy.

To configure the number of backup set copies, specify an integer. The following examples show possible configurations:

# Makes 2 disk copies of each datafile and control file backup set
# (autobackups excluded)
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 2;
# Makes 3 copies of every archived redo log backup to tape
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE sbt TO 3;

If you use the duplexing feature in conjunction with multiple FORMAT strings, then you can name each individual backup set copy. For example, assume that you configure BACKUP COPIES to 3. Then, you can issue:

BACKUP DATABASE FORMAT '/tmp/%U', '?/dbs/%U', '?/oradata/%U';

RMAN generates 3 identical copies of each backup piece in the backup set, and names each piece according to the specified FORMAT string: the first copy is placed in the /tmp directory, the second in the ?/dbs directory, and the third in the ?/oradata directory. Note that you can specify the FORMAT string on the BACKUP, CONFIGURE CHANNEL, and ALLOCATE CHANNEL commands.

To return a BACKUP COPIES configuration to its default value, run the same CONFIGURE command with the CLEAR option, as in this example:

CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE sbt CLEAR;

By default, CONFIGURE ... BACKUP COPIES is set to 1 for each device type.

Note:

If you do not want to create a persistent copies configuration, then you can specify copies with the BACKUP COPIES and SET BACKUP COPIES commands.

Showing the Configured Degree of Duplexing: SHOW... BACKUP COPIES

SHOW... BACKUP COPIES lets you view how you have used CONFIGURE ... BACKUP COPIES command to set the number of identical copies that RMAN makes of each of several types of backup.

After connecting to the target database and recovery catalog (if you use one), run the SHOW ARCHIVELOG BACKUP COPIES or SHOW DATAFILE BACKUP COPIES commands. For example, enter:

SHOW DATAFILE BACKUP COPIES;    # shows CONFIGURE DATAFILE BACKUP COPIES setting

Sample output for SHOW DATAFILE BACKUP COPIES follows:

RMAN configuration parameters are:
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default