Configuring a stream-based Oracle backup
The following procedure explains how to reconfigure an existing Oracle RMAN specification to achieve a stream-based, optimized, deduplicated Oracle backup.
To configure a stream-based Oracle backup
- On the client computer that hosts the Oracle database, open the RMAN backup script in a text editor, and make the following edits:
Add the FILESPERSET=1 parameter to the part of the RMAN script that specifies how you want to back up the database.
Do not add FILESPERSET=1 to the section of the RMAN script that specifies how to back up the control files or archive logs. Typically, these other data objects are unique to each backup, so there is very little potential gain from optimizing the control file and archive log backups for deduplication.
Example RMAN script after editing:
BACKUP FILESPERSET=1 %BACKUP_TYPE% FORMAT 'bk_u%%u_s%%s_p%%p_t%%t' DATABASE;
The addition of FILESPERSET=1 suppresses Oracle multiplexing of more than one data file into a backup set. When you suppress Oracle multiplexing, Oracle creates the backup set identically each time the backup runs. NetBackup can deduplicate these identical backup sets.
Specify parallel backup streams for the database backup.
Specify appropriate ALLOCATE CHANNEL and RELEASE CHANNEL parameters in the backup script.
For an example that shows an edited backup script, see the following:
- Disable Oracle's optimization and encryption for the duration of the database backup.
By default, Oracle disables optimization and encryption. If optimization and encryption are enabled, run the following RMAN commands from the command line to disable optimization and encryption:
RMAN> CONFIGURE BACKUP OPTIMIZATION OFF; RMAN> CONFIGURE ENCRYPTION FOR DATABASE OFF;
If your site requires encryption, you can specify encryption in the NetBackup for Oracle backup policy.
- Disable Oracle's compression for the duration of the database backup.
By default, Oracle disables compression. If compression is enabled, Oracle compresses unused sections in streams, and the result is unpredictable deduplication rates. If compression is enabled, run the following RMAN command from the command line to disable compression:
RMAN> CONFIGURE DEVICE TYPE SBT_TAPE BACKUP TYPE TO BACKUPSET;
If your site requires compression, you can specify compression in the NetBackup for Oracle backup policy.
- Configure a NetBackup for Oracle policy.
If you want to compress or encrypt the backup, enable compression and encryption in the NetBackup pd.conf file.
Run a full database backup as soon as you can. The policy can perform incremental backups until the full backup can be run.
Note:
Make sure that Oracle optimization, encryption, and compression are disabled for the entirety of the database backup. Make sure to check specifications outside of the RMAN backup script, too.