Question on OCR

[satish]

Dear Erman,

We have a diskgroup OCRVOTE with high redundancy with 5 disks in it(voting disks,ocr,spfile)

[oraprod@nodedb1~]$ crsctl query css votedisk
##  STATE    File Universal Id                File Name Disk group
--  -----    -----------------                --------- ---------
 1. ONLINE   6fb40aef67204fe4bf05bc2f1ab60193 (ORCL:OCRVOTEDISK1) [OCRVOTE]
 2. ONLINE   4b4bc9248bbc4f49bf4368c35b1486b8 (ORCL:OCRVOTEDISK2) [OCRVOTE]
 3. ONLINE   ab2c12b26bff4f35bf5ffc92bcb88f01 (ORCL:OCRVOTEDISK3) [OCRVOTE]
 4. ONLINE   103f927bff5f4fb6bfff9c4ab7ccea00 (ORCL:OCRVOTEDISK4) [OCRVOTE]
 5. ONLINE   c7f6893759c14fc2bf01b347d38e9fdb (ORCL:OCRVOTEDISK5) [OCRVOTE]
Located 5 voting disk(s).

I agree for high redundancy diskgroup,we will have 3 OCR copies.

If any of the OCR copy is corrupted,will oracle take care of it by reading other copies and writing to the corrupted one?
OR
Do we need to take any manual action

Thank you

[ErmanArslansOracleBlog]

You need to take manual actions, as documented in "How to Replace a Corrupt OCR Mirror File (Device/File Needs To Be Synchronized With The Other Device) (Doc ID 317628.1)"

Ex: CRS_HOME/bin/ocrconfig -replace .........

[satish]

Thanks for the update erman

In our case,we are not using OCRMIRROR.we only have OCR in one diskgroup with high redundancy

[oraprod@node1~]$ ocrcheck
Status of Oracle Cluster Registry is as follows :
         Version                  :          4
         Total space (kbytes)     :     409568
         Used space (kbytes)      :       1696
         Available space (kbytes) :     407872
         ID                       : 1852974648
         Device/File Name         :   +OCRVOTE
                                    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 bypassed due to non-privileged user

[oraprod@node1~]$


According to oracle,in high redundancy diskgroup,we will have 3 OCR copies.My concern here is,if any of the copy gets corrupted,then will oracle repair the corrupted copy automatically?

Thanks for all the support

[ErmanArslansOracleBlog]

Are you asking about OCR or voting files?
Please first clarify that..

Also, ASM mirroring is in ASM level.. So you have mirror copies on Storage level, but if you corrupt your OCR file , then this is something different, since it is a corruption on file level.

As for OCR,

If you corrupt your OCR (supposing you have single OCR), then you should restore the OCR from backup..

ocrconfig -showbackup
ocrconfig -restore

If you haven't a valid OCR backup, you should reinitialize OCR  ->

For 10.2 and 11.1:
Please refer to How to Recreate OCR/Voting Disk Accidentally Deleted Document 399482.1

For 11.2+:
Deconfig the clusterware stack and rerun root.sh on all nodes is required.

Note that,

Oracle recommends that you configure at least two OCR locations if OCR is configured on an Oracle ASM disk group. You should configure OCR in two independent disk groups.

[Sri]

Thanks for the update.

We have 5 vitedisks.If one voting disk is corrupted,then will oracle repair it automatically?

[ErmanArslansOracleBlog]

It recovers/replaces it, but there is one condition as stated in Oracle's Clusterware Administration and Deployment Guide

->

If voting disks are stored on Oracle ASM with normal or high redundancy, and the storage hardware in one failure group suffers a failure, then "if there is another disk available in a disk group in an unaffected failure group", Oracle ASM recovers the voting disk in the unaffected failure group.

[Sri]

Thank you erman. It clarified