OCRCHECK utility

Have a Very Happy New Year 2012 to everyone.

OCRCHECK utility is used to verify the OCR integrity. The OCRCHECK utility displays the version of the OCR's block format, total space available and used space, OCRID, and the OCR locations that you have configured. OCRCHECK performs a block-by-block checksum operation for all of the blocks in all of the OCRs that you have configured. It also returns an individual status for each file as well as result for the overall OCR integrity check. The following is a sample of the OCRCHECK output:
Status of Oracle Cluster Registry is as follows :

Version : 2 Total space (kbytes) : 262144 Used space (kbytes) : 16256 Available space (kbytes) : 245888 ID : 1918913332 Device/File Name : /dev/raw/raw1 Device/File integrity check succeeded Device/File Name : /oradata/mirror.ocr Device/File integrity check succeeded Cluster registry integrity check succeeded

OCRCHECK creates a log file in the directory CRS_Home/log/hostname/client. To change amount of logging, edit the file CRS_Home/srvm/admin/ocrlog.ini

To remove an OCR location from your Oracle RAC environment:

Use the OCRCHECK utility to ensure that at least one OCR other than the OCR that you are removing is online.
> ocrcheck

Do not perform this OCR removal procedure unless there is at least one active OCR online.
Run the following comman on any node in the cluster to remove one copy of the OCR:
ocrconfig -replace ocr

This command updates the OCR configuration on all the nodes on which Oracle Clusterware is running.
Recovering the OCR

The first method uses automatically generated OCR file copies and the second method uses manually created OCR export files.

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