The Master Node of RAC Cluster

The ways to find master node in Oracle RAC environment.

1) Check from ocssd.log
$ cat $GRID_HOME/log/racnode1/cssd/ocssd.l* |grep 'master node' |tail -1 2017-07-18 10:09:21.431: [ CSSD][1102125408]clssgmCMReconfig: reconfiguration successful, incarnation 217002855 with 2 nodes, local node number 2, master node number 2
2) Check from crsd.log
$ cat $GRID_HOME/log/racnode1/crsd/crsd.l* |grep 'OCR MASTER' | tail -1
2017-07-18 10:09:10.414: [ OCRMAS][1101056352]th_master:13: I AM THE NEW OCR MASTER at incar 18. Node Number 2
3) Check who ( MASTER ) does OCR backup
grid@racnode1:$ ocrconfig -showbackup

racnode2 2017/07/17 13:51:21 /u01/app/11.2.0.4/grid/cdata/RACNODE-CLUSTER/backup00.ocr
racnode2 2017/07/17 09:51:18 /u01/app/11.2.0.4/grid/cdata/RACNODE-CLUSTER/backup01.ocr
racnode2 2017/07/17 05:51:16 /u01/app/11.2.0.4/grid/cdata/RACNODE-CLUSTER/backup02.ocr
racnode2 2017/07/16 05:51:00 /u01/app/11.2.0.4/grid/cdata/RACNODE-CLUSTER/day.ocr
racnode2 2017/07/06 01:48:12 /u01/app/11.2.0.4/grid/cdata/RACNODE-CLUSTER/week.ocr
PROT-25: Manual backups for the Oracle Cluster Registry are not available