Adding an OCR (Oracle Cluster Registry):-
You can also add an OCR after completing the Oracle RAC installation, if you didn’t mirror the OCR during installation. Please note that you must run all the commands as “root”.
Run the below command to add OCR MIRROR.
#ocrconfig -replace ocrmirror
Removing an Oracle Cluster Registry (OCR)
To remove OCR/OCR MIRROR the other OCR must be online.
Run the below command on any node to remove OCR.
# ocrconfig -replace ocr
Run the below command on any node to remove OCR Mirror.
# ocrconfig -replace ocrmirror
Please note that these commands update the OCR configuration on all of the nodes where Oracle Clusterware is running.
Click here to learn How to backup and recover Oracle Cluster Registry.