How to Find OCR Master Node in RAC   Leave a comment

1. The default OCR master is always the first node that’s started in the cluster.

2. When OCR master (crsd.bin process) stops or restarts for whatever reason, the crsd.bin on surviving node with lowest node number will become new OCR master.

The following method can be used to find OCR master:

1. By searching crsd.l* on all nodes:

grep “OCR MASTER” $GRID_HOME/log/$HOST/crsd/crsd.l*

*In my case i have exported ORACLE_HOME to /u01/app/11.2.0/grid

so it is like

grep “OCR MASTER” $ORACLE_HOME/log/$HOST/crsd/crsd.l*

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If there’s output, the last line will show who OCR master is. If the cluster has been up and running on all nodes for a long while, as crsd.log keeps rotating to crsd.l01, and crsd.l01 to crsd.l02 till crsd.l10, there’s a chance the above grep command will not return anything. If that’s the case, see Step 2.

2. By locating automatic OCR backup:

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OCR automatic backup is done by OCR master every 4 hours. In above example, latest automatic backup was done around 2013/12/06 15:21:04  by racnode1 which means racnode1 was and may still be OCR master since 2013/12/06 15:21:04 .

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Posted December 10, 2013 by balaoracledba.com in OracleRAC

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