CRS and Voting - Backup and Recovery

CRS and Voting Loss

backup for CRS and Voting file is based on dd

a) CRS loss

rm –f /oracle01/oracrs/ocr.dbf

[oracle@orcl-experts crsd]$ rm -f /oracle01/oracrs/ocr.dbf

Impact: No impact on node apps

In event of a failure, before you attempt to restore the OCR, ensure that the OCR is unavailable. Run the following command to check the status of the OCR:
ocrcheck

[oracle@orcl-experts crsd]$ ocrcheck
PROT-602: Failed to retrieve data from the cluster registry

[oracle@orcl-experts crsd]$ cluvfy comp ocr -n all

Verifying OCR integrity

Checking OCR integrity...

Checking the absence of a non-clustered configuration...
All nodes free of non-clustered, local-only configurations.

ERROR:
Unable to obtain OCR integrity details from any of the nodes.

OCR integrity check failed.

Verification of OCR integrity was unsuccessful on all the nodes.

Restore:
Stop the Clusterware in all the nodes

[root@orcl-experts ~]# /etc/init.d/init.crs stop
Shutting down Oracle Cluster Ready Services (CRS):
OCR initialization failed accessing OCR device: PROC-26: Error while accessing the physical storage Operating System error [No such file or directory] [2]
Shutdown has begun. The daemons should exit soon.
[root@orcl-experts ~]#
[root@orcl-experts ~]# /etc/init.d/init.crs stop
Shutting down Oracle Cluster Ready Services (CRS):
OCR initialization failed accessing OCR device: PROC-26: Error while accessing the physical storage Operating System error [No such file or directory] [2]
Shutdown has begun. The daemons should exit soon.
[root@orcl-experts ~]#

[root@orcl-experts ~]# dd if=/data01/home/oracle/voting_backup/ocrbp.dbf of=/oracle01/oracrs/ocr.dbf
20480+0 records in
20480+0 records out
[root@orcl-experts ~]# chown root:oinstall /oracle01/oracrs/ocr.dbf

Bring up the cluster in all the nodes

[oracle@orcl-experts ~]$ ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 2
Total space (kbytes) : 262120
Used space (kbytes) : 3776
Available space (kbytes) : 258344
ID : 767132006
Device/File Name : /oracle01/oracrs/ocr.dbf
Device/File integrity check succeeded

Device/File not configured

Cluster registry integrity check succeeded

[oracle@orcl-experts ~]$

b) Voting file
The Voting Disk is used by the Oracle cluster manager in various layers. The Node Monitor (NM) uses the Voting Disk for the Disk Hearbeat, which is essential in the detection and resolution of cluster "split brain". NM monitors the Voting Disk for other competing sub-clusters and uses it for the eviction phase. Hence the availability from the Voting Disk is critical for the operation of the Oracle Cluster Manager.

There are 2 methods to recover from the voting file failure
a) use dd to restore voting file from the backup – Recommended
b) Re-install CRS

Note: As per the testing, please make sure to change the owner ship and permission on the voting files.

#chown root:oinstall <voting file>
#chmod 666 <voting file>