Oracle RAC 11gR2 Administration Tips

Determine Location of Voting Disk

#crsctl query css votedisk

Determine OCR Location

#cat /etc/oracle/ocr.loc

Check Integrity of Oracle Clusterware Configuration files, check ocssd.log file for Voting Disk errors

#grep voting <GI Home>/log/hostname/cssd/ocssd.log

Use cluvfy or ocrcheck utility

$cluvfy comp ocr -n all -verbose
$ocrcheck
*run as root user to check logical corruption

Backing Up and Recovering the Voting Disk

In 11gR2 ,Voting Disk data is backed up automatically in OCR as part of configuration change.On non-asm storage, we can remove voting disks and add them back by following commands

$crsctl delete css votedisk <path_to_voting_disk>
$crsctl add css votedisk <path_to_voting_disk>

Add a voting disk to ASM

#crsctl replace votedisk +asm_disk_group

To migrate voting disks from Non-asm storage devices to ASM or vice versa

#crsctl replace votedisk {+asm_disk_group|path_to_voting disk}

Locating OCR Automatic Backups(default location <Grid Home>/cdata/<cluster name>

$ocrconfig -showbackup auto

Changing the Automatic OCR Backup Location

$ocrconfig -backuploc <path to shared NFS or CFS>
Because the automatic backup is performed only by the master node to the local file system by default ,it is recommended that you change the OCR automatic backup location to one that is shared by all nodes in the cluster.

Recovering the OCR by using Physical Backups

1.Locate a physical backup
$ocrconfig -showbackup

2.stop oracle clusterware stack on all nodes
#crsctl stop cluster -all

3.Stop Oracle high availability deamon services on all nodes

#crsctl stop crs

4.Restore the physical OCR backup
#ocrconfig -restore /u01/app/11.2.0/../cdata/cluster01/day.ocr

5.Restart Oracle High Availability Services on all nodes
#crsctl start crs

6. Check the OCR integrity
$cluvfy comp ocr -n all