RESTORE LOST OCR FROM BACKUP ORACLE RAC

RESTORE LOST OCR FROM BACKUP ORACLE RAC

In oracle RAC , by default ocr backup is taken for every four hours in a day from master node, once in a day and once in a weekend. As you know ,OCR file is critical file which stores the cluster information and crs process reads the OCR to start the cluster vital resources.

If unfortunately , we lost the ocr file or the file got corrupted due to some reason.Then we need to restore the corrupted file using the backup

Identify the recent backup of ocr file

[oracle@exdbadm01 ~]$ ocrconfig -showbackup

exdbadm02     2021/06/16 20:24:37     /u01/app/11.2.0/cdata/exdbadm-scan/backup00.ocr

exdbadm02     2021/06/15 21:42:14     /u01/app/11.2.0/cdata/exdbadm-scan/backup01.ocr

exdbadm02     2021/06/15 17:42:13     /u01/app/11.2.0/cdata/exdbadm-scan/backup02.ocr

exdbadm02     2021/06/15 17:42:13     /u01/app/11.2.0/cdata/exdbadm-scan/day.ocr

exdbadm02     2021/06/11 21:06:55     /u01/app/11.2.0/cdata/exdbadm-scan/week.ocr
PROT-25: Manual backups for the Oracle Cluster Registry are not available

Stop clusterware on all the RAC nodes

[root@exdbadm01 oracle]# crsctl stop cluster -all
CRS-2673: Attempting to stop 'ora.crsd' on 'exdbadm01'
CRS-2673: Attempting to stop 'ora.crsd' on 'exdbadm02'
CRS-2790: Starting shutdown of Cluster Ready Services-managed resources on 'exdbadm01'
CRS-2673: Attempting to stop 'ora.LISTENER.lsnr' on 'exdbadm01'
CRS-2673: Attempting to stop 'ora.DATA2.dg' on 'exdbadm01'
CRS-2673: Attempting to stop 'ora.MGMT.dg' on 'exdbadm01'
CRS-2673: Attempting to stop 'ora.registry.acfs' on 'exdbadm01'
CRS-2673: Attempting to stop 'ora.DATA.dg' on 'exdbadm01'
CRS-2673: Attempting to stop 'ora.FRA.dg' on 'exdbadm01'
CRS-2790: Starting shutdown of Cluster Ready Services-managed resources on 'exdbadm02'
CRS-2673: Attempting to stop 'ora.LISTENER_SCAN1.lsnr' on 'exdbadm02'
CRS-2673: Attempting to stop 'ora.oc4j' on 'exdbadm02'
CRS-2673: Attempting to stop 'ora.LISTENER.lsnr' on 'exdbadm02'
CRS-2673: Attempting to stop 'ora.cvu' on 'exdbadm02'
CRS-2673: Attempting to stop 'ora.DATA2.dg' on 'exdbadm02'
CRS-2673: Attempting to stop 'ora.MGMT.dg' on 'exdbadm02'
CRS-2673: Attempting to stop 'ora.registry.acfs' on 'exdbadm02'
CRS-2673: Attempting to stop 'ora.DATA.dg' on 'exdbadm02'
CRS-2673: Attempting to stop 'ora.FRA.dg' on 'exdbadm02'
CRS-2677: Stop of 'ora.LISTENER.lsnr' on 'exdbadm01' succeeded

Restore the file from backup

[root@exdbadm01 oracle]# ocrconfig -restore /u01/app/11.2.0/cdata/exdbadm-scan/backup00.ocr

Start clusterware from all nodes

[root@exdbadm01 oracle]# crsctl start cluster -all
CRS-2672: Attempting to start 'ora.mdnsd' on 'exdbadm01'
CRS-2676: Start of 'ora.mdnsd' on 'exdbadm01' succeeded
CRS-2672: Attempting to start 'ora.gpnpd' on 'exdbadm01'
CRS-2676: Start of 'ora.gpnpd' on 'exdbadm01' succeeded
CRS-2672: Attempting to start 'ora.gipcd' on 'exdbadm01'
CRS-2672: Attempting to start 'ora.cssdmonitor' on 'exdbadm01'
CRS-2676: Start of 'ora.cssdmonitor' on 'exdbadm01' succeeded
CRS-2676: Start of 'ora.gipcd' on 'exdbadm01' succeeded
CRS-2672: Attempting to start 'ora.cssd' on 'exdbadm01'
CRS-2672: Attempting to start 'ora.diskmon' on 'exdbadm01'
CRS-2676: Start of 'ora.diskmon' on 'exdbadm01' succeeded
CRS-2676: Start of 'ora.cssd' on 'exdbadm01' succeeded
CRS-2672: Attempting to start 'ora.ctssd' on 'exdbadm01'
CRS-2676: Start of 'ora.ctssd' on 'exdbadm01' succeeded
CRS-2672: Attempting to start 'ora.evmd' on 'exdbadm01'
CRS-2672: Attempting to start 'ora.drivers.acfs' on 'exdbadm01'
CRS-2679: Attempting to clean 'ora.cluster_interconnect.haip' on 'exdbadm01'
CRS-2681: Clean of 'ora.cluster_interconnect.haip' on 'exdbadm01' succeeded
CRS-2672: Attempting to start 'ora.cluster_interconnect.haip' on 'exdbadm01'
CRS-2676: Start of 'ora.evmd' on 'exdbadm01' succeeded
CRS-2676: Start of 'ora.drivers.acfs' on 'exdbadm01' succeeded
CRS-2676: Start of 'ora.cluster_interconnect.haip' on 'exdbadm01' succeeded
CRS-2672: Attempting to start 'ora.asm' on 'exdbadm01'
CRS-2676: Start of 'ora.asm' on 'exdbadm01' succeeded
CRS-2672: Attempting to start 'ora.crsd' on 'exdbadm01'
CRS-2676: Start of 'ora.crsd' on 'exdbadm01' succeeded

Perform OCR integrity check for any logical corruption on the OCR contents

[root@exdbadm01 oracle]# ocrcheck
Status of Oracle Cluster Registry is as follows :
         Version                  :          3
         Total space (kbytes)     :     262120
         Used space (kbytes)      :       3108
         Available space (kbytes) :     259012
         ID                       : 1425936166
         Device/File Name         :      +MGMT
                                    Device/File integrity check succeeded

                                    Device/File not configured

                                    Device/File not configured

                                    Device/File not configured

                                    Device/File not configured

         Cluster registry integrity check succeeded

         Logical corruption check succeeded

Execute the below command to check ocr integrity at cluster level

[oracle@exdbadm01 ~]$ cluvfy comp ocr

Verifying OCR integrity

Checking OCR integrity...

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


ASM Running check passed. ASM is running on all specified nodes

Checking OCR config file "/etc/oracle/ocr.loc"...

OCR config file "/etc/oracle/ocr.loc" check successful


Disk group for ocr location "+MGMT" available on all the nodes


NOTE:
This check does not verify the integrity of the OCR contents. Execute 'ocrcheck' as a privileged user to verify the contents of OCR.

OCR integrity check passed

Verification of OCR integrity was successful.

Verify the votedisk

[oracle@exdbadm01 ~]$ crsctl query css votedisk
##  STATE    File Universal Id                File Name Disk group
--  -----    -----------------                --------- ---------
 1. ONLINE   904cf1d369404f4dbf9db5cefbffdcc9 (o/192.168.56.33/MGMT_CD_cell09_stocell) [MGMT]
Located 1 voting disk(s).