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Oracle Database load balanced RAC backup limitation

Created: 06 Mar 2012
Dfrederi53's picture
2 Agree
0 Disagree
+2 2 Votes
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There is an Oracle RMAN limitation with BUE, which is that you cannot run a parallel backup across multiple nodes on an Oracle RAC Cluster.  For example if you run:

RUN {
ALLOCATE CHANNEL ch00 TYPE 'SBT_TAPE' CONNECT='sys/welcome1@pbrlight1';
ALLOCATE CHANNEL ch01 TYPE 'SBT_TAPE' CONNECT='sys/welcome1@pbrlight2;
SEND 'BSA_SERVICE_HOST=x4200-02a,NBBSA_DB_DEVICE_NAME=Oracle-Linux::\\RAC-pbrlight-1458682921\pbrlight';
BACKUP AS BACKUPSET DATABASE INCLUDE CURRENT CONTROLFILE PLUS ARCHIVELOG;
RELEASE CHANNEL ch00;
RELEASE CHANNEL ch01;
}

This will not work because you are trying to spread the backup load across two nodes (connect string to each channel is for a different host) and Backup Exec is not capable of handling this type of configuration (we did verify this information with Symantec).

If you run:

RUN {
ALLOCATE CHANNEL ch00 TYPE 'SBT_TAPE';
ALLOCATE CHANNEL ch00 TYPE 'SBT_TAPE';
SEND 'BSA_SERVICE_HOST=x4200-02a,NBBSA_DB_DEVICE_NAME=Oracle-Linux::\\RAC-pbrlight-1458682921\pbrlight';
BACKUP AS BACKUPSET DATABASE INCLUDE CURRENT CONTROLFILE PLUS ARCHIVELOG;
RELEASE CHANNEL ch00
RELEASE CHANNEL ch01;
}

This will work because you are allocating both channels from the local node where the script is being run. The entire database is still backed up, but only one node is processing the backup.   Depending on the backup configuration this may have no impact on the setup, However many customers require this type of setup to evenly utilize available resources and for high availability (backup runs on either node).