OCR & Voting Disks - Oracle RAC

A long weekend is always a good thing. When you combine that with the ability to literally “get away from it all”, they are even better :)  After so many days,  am able to publish my work am glad about it. Here I present one of my recent works :-

Oracle Clusterware includes two important components: the voting disk and the Oracle Cluster Registry (OCR). The voting disk is a file that manages information about node membership and the OCR is a file that manages cluster and RAC database configuration information.

Oracle recommends that you select the option to configure multiple voting disks during Oracle Clusterware installation to improve availability.

Backing up Voting Disks

Run the following command to back up a voting disk. Perform this operation on every voting disk as needed where voting_disk_name is the name of the active voting disk and backup_file_name is the name of the file to which you want to back up the voting disk contents:

dd if=voting_disk_name of=backup_file_name

Recovering Voting Disks

Run the following command to recover a voting disk where backup_file_name is the name of the voting disk backup file and voting_disk_name is the name of the active voting disk:

dd if=backup_file_name of=voting_disk_name

Note: If you have multiple voting disks, then you can remove the voting disks and add them back into your environment using the crsctl delete css votedisk path and crsctl add css votedisk path commands respectively, where path is the complete path of the location on which the voting disk resides.

Changing the Voting Disk Configuration after Installing Real Application Clusters

You can dynamically add and remove voting disks after installing Real Application Clusters. Do this using the following commands where path is the fully qualified path for the additional voting disk. Run the following command as the root user to add a voting disk:

crsctl add css votedisk path

Run the following command as the root user to remove a voting disk:

crsctl delete css votedisk path

Changing the location of Voting disks

Login as root, group dba

Shutdown CRS on all nodes:
 ./crsctl stop crs

cross checking the status:
 ./crsctl check crs

Check the the location of the voting disk:
 ./crsctl query css votedisk

Copy the voting disk to the new location:

Change the location in CRS:
 ./crsctl add css votedisk
[Repeat step if more voting disks need to be added]

Delete the old Voting Disks:
crsctl delete css votedisk

Changing the location of OCR

Login as root, group dba

Start CRS on all nodes:

 ./crsctl start crs

 ./crsctl check crs

Check OCR configuration/backups:

 ocrcheck

 ocrconfig -showbackup

Copy the OCR mirror to the new location:

Check the files in the new location:

 ls -rlt

 cp crs_mirror /mnt/prdaudit_crs_mirror1

Change the OCR location in the CRS:

 ./ocrconfig -replace ocrmirror [path for ocrmirror]

Same way to move the ocr:

oraconfig -replace ocr 

then run the check command:

 ocrcheck

if everything seems right:

 exit 

These are the vital tasks which are associated with Voting Disks & OCR of Oracle Clusterware. use the article for your references to save lot of time :)

See you next time......