Enhancing Oracle RAC Backup Performance

Several options are available for enhancing backup performance and reduce the network bandwidth used for performing backups. These options include:

• Specifying the number of datafiles and archive files to be included in each RMAN backupset. The default value is 32.

• Limiting the maximum size for each RMAN backupset. By default no limits are defined. By default no limits are defined.

• Limiting the number of open datafiles that can be read by RMAN during the backup. The default value is 8.

• Limiting the maximum size of data blocks used during backups. The default value is 262144 Kb.

• Specifying the section size for Oracle 11g multisection backups. This enables you to divide large data files into multiple sections and simultaneously backup the data file across multiple channels.

  If the section size is larger than the data file size, multisection backup is not used for the file. If the section size is very small such that more than 256 sections would be produced, RMAN increases the section size such that 256 sections are created.

In addition to the above configurations, you can also enable distribution of data across disks during backup operations. See Performance Tuning for more details.

Procedure

1. From the CommCell Browser, navigate to Client Computers | <RAC Client> | < Instance>.

2. Right-click the <Subclient>, and then click Properties.

3. Click the Advanced tab.

4. In the Data Files (BFS) box, type or select the number of datafiles to be bundled in each RMAN backup set.

5. In the Archive Files (BFS) box, type or select the number of archive files in each RMAN backup set.

6. In the Backup Set Size group box, do one of the following:

   • Click Maximum Size and type or select the size of backup set allowed for RMAN backup set.

   • Click Section Size and type or select the size of each data file section used in an RMAN backup set for Oracle 11g backups.

7. In the Maximum No. Of Open Files box, type or select the number of datafiles that RMAN can read from simultaneously during a backup operation.

8. Click OK.

9. From the CommCell Browser, navigate to Client Computers | <RAC Client>.

10. Right-click the <*Instance*>, and then click Properties.

11. Click the Details tab.

12. In the Block Size box, type or select the size of the block for backup and restore operations.

13. Click OK.