Finding CRS master node

check the crsd.log

cd $ORACLE_HOME/log/crsd/crsd.log

2010-02-05 02:32:32.139: [ OCRMAS][3348]th_master:13: I AM THE NEW OCR MASTER at incar 67. Node Number 3

This means that we had another incarnation and the master node is 2.

Confusing a little beat. This is happening because the logs rotate or are write in a matter of events happening between the nodes.

So for my opinion please check the crsd.log from each node and the master is the one in the latest incarnation.

e.g

From node1 crsd.log :
2010-02-02 13:05:44.424: [ OCRMAS][3348]th_master:13: I AM THE NEW OCR MASTER at incar 62. Node Number 1

From node2 crsd.log :
2010-01-18 09:58:19.932: [ OCRMAS][3352]th_master:13: I AM THE NEW OCR MASTER at incar 53. Node Number 2

From node3 crsd.log :
2010-02-05 02:32:32.139: [ OCRMAS][3348]th_master:13: I AM THE NEW OCR MASTER at incar 67. Node Number 3

So the master node is 3 !!!

You can also check with :

ocrconfig -showbackup

where the latest backup is, that's the master node. But remember that by default ocrbackups are taken every 4 hours.

OR

I have RAC 4 nodes and need to know master node:

-I have RAC 4 nodes and need to know master node:

- Use ocrconfig -showbackup
Oracle backup OCR file automatic on master node, So check OCR backup information be able help.

$ ocrconfig -showbackup

node04 2009/07/21 23:10:38 /u01/oracle/product/crs/cdata/crs
node04 2009/07/21 19:10:38 /u01/oracle/product/crs/cdata/crs
node04 2009/07/21 15:10:38 /u01/oracle/product/crs/cdata/crs
node04 2009/07/20 23:10:36 /u01/oracle/product/crs/cdata/crs
node04 2009/07/08 11:10:14 /u01/oracle/product/crs/cdata/crs

that mean master node be "node04"
more
- grep -i "master node" ocssd.log | tail -1 at ORA_CRS_HOME/log/nodename/cssd/ path.
But perhaps not see in ocssd.log file.