Doc ID 428681.1

Applies to:

Goal

The goal of this note is to provide steps to add, remove, replace or move an Oracle Cluster Repository (OCR) and/or Voting Disk in Oracle Clusterware 10gR2, 11gR1 and 11gR2 environment. It will also provide steps to move OCR / voting and ASM devices from raw device to block device. For Oracle Clusterware 12c, please refer to Document 1558920.1 Software Patch Level and 12c Grid Infrastructure OCR Backup/Restore.

This article is intended for DBA and Support Engineers who need to modify, or move OCR and voting disks files, customers who have an existing clustered environment deployed on a storage array and might want to migrate to a new storage array with minimal downtime.

Typically, one would simply cp or dd the files once the new storage has been presented to the hosts. In this case, it is a little more difficult because:

1. The Oracle Clusterware has the OCR and voting disks open and is actively using them. (Both primary and mirrors)
2. There is an API provided for this function (ocrconfig and crsctl), which is the appropriate interface than typical cp and/or dd commands.

It is highly recommended to take a backup of the voting disk, and OCR device before making any changes.

Solution

Prepare the disks

For OCR or voting disk addition or replacement, new disks need to be prepared. Please refer to Clusteware/Gird Infrastructure installation guide for different platform for the disk requirement and preparation.

1. Size

For 10.1:
OCR device minimum size (each): 100M
Voting disk minimum size (each): 20M

For 10.2:
OCR device minimum size (each): 256M
Voting disk minimum size (each): 256M

For 11.1:
OCR device minimum size (each): 280M
Voting disk minimum size (each): 280M

For 11.2:
OCR device minimum size (each): 300M
Voting disk minimum size (each): 300M

2. For raw or block device (pre 11.2)

Please refer to Clusterware installation guide on different platform for more details.
On windows platform the new raw device link is created via $CRS_HOME\bin\GUIOracleOBJManager.exe, for example:
\\.\VOTEDSK2
\\.\OCR2

3. For ASM disks (11.2+)

On Windows platform, please refer to Document 331796.1 How to setup ASM on Windows
On Linux platform, please refer to Document 580153.1 How To Setup ASM on Linux Using ASMLIB Disks, Raw Devices or Block Devices?
For other platform, please refer to Clusterware/Gird Infrastructure installation guide on OTN (Chapter: Oracle Automatic Storage Management Storage Configuration).

4. For cluster file system

If OCR is on cluster file system, the new OCR or OCRMIRROR file must be touched before add/replace command can be issued. Otherwise PROT-21: Invalid parameter (10.2/11.) or PROT-30 The Oracle Cluster Registry location to be added is not accessible (for 11.2) will occur.

It is not required to pre-touch voting disk file on cluster file system.

After delete command is issued, the ocr/voting files on the cluster file system require to be removed manually.

5. Permissions

For OCR device:
chown root:oinstall <OCR device>
chmod 640 <OCR device>

For Voting device:
chown <crs/grid>:oinstall <Voting device>
chmod 644 <Voting device>

For ASM disks used for OCR/Voting disk:
chown griduser:asmadmin <asm disks>
chmod 660 <asm disks>

6. Redundancy

For Voting disks (never use even number of voting disks):
External redundancy requires minimum of 1 voting disk (or 1 failure group)
Normal redundancy requires minimum of 3 voting disks (or 3 failure group)
High redundancy requires minimum of 5 voting disks (or 5 failure group)

Insufficient failure group in respect of redundancy requirement could cause voting disk creation failure. For example: ORA-15274: Not enough failgroups (3) to create voting files

For OCR:
10.2 and 11.1, maximum 2 OCR devices: OCR and OCRMIRROR
11.2+, upto 5 OCR devices can be added.

For more information, please refer to platform specific Oracle® Grid Infrastructure Installation Guide.

ADD/REMOVE/REPLACE/MOVE OCR Device

Make sure there is a recent copy of the OCR file before making any changes:

ocrconfig -showbackup

If there is not a recent backup copy of the OCR file, an export can be taken for the current OCR file. Use the following command to generate an export of the online OCR file:

In 10.2

# ocrconfig -export <OCR export_filename> -s online

In 11.1 and 11.2

# ocrconfig -manualbackup
node1 2008/08/06 06:11:58 /crs/cdata/crs/backup_20080807_003158.ocr

To recover using this file, the following command can be used:

From 11.2+, please also refer How to restore ASM based OCR after complete loss of the CRS diskgroup on Linux/Unix systems Document 1062983.1

To see whether OCR is healthy, run an ocrcheck, which should return with like below.

# ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 2
Total space (kbytes) : 497928
Used space (kbytes) : 312
Available space (kbytes) : 497616
ID : 576761409
Device/File Name : /dev/raw/raw1
Device/File integrity check succeeded
Device/File Name : /dev/raw/raw2
Device/File integrity check succeeded

Cluster registry integrity check succeeded

For 11.1+, ocrcheck as root user should also show:
Logical corruption check succeeded

1. To add an OCRMIRROR device when only OCR device is defined:

To add an OCR mirror device, provide the full path including file name.
10.2 and 11.1:

# ocrconfig -replace ocrmirror <filename>
eg:
# ocrconfig -replace ocrmirror /dev/raw/raw2
# ocrconfig -replace ocrmirror /dev/sdc1
# ocrconfig -replace ocrmirror /cluster_fs/ocrdisk.dat
> ocrconfig -replace ocrmirror \\.\OCRMIRROR2  - for Windows

11.2+: From 11.2 onwards, upto 4 ocrmirrors can be added

# ocrconfig -add <filename>
eg:
# ocrconfig -add +OCRVOTE2
# ocrconfig -add /cluster_fs/ocrdisk.dat

2. To remove an OCR device

To remove an OCR device:
10.2 and 11.1:

# ocrconfig -replace ocr

11.2+:

# ocrconfig -delete <filename>
eg:
# ocrconfig -delete +OCRVOTE1

* Once an OCR device is removed, ocrmirror device automatically changes to be OCR device.
* It is not allowed to remove OCR device if only 1 OCR device is defined, the command will return PROT-16.

To remove an OCR mirror device:
10.2 and 11.1:

# ocrconfig -replace ocrmirror

11.2+:

# ocrconfig -delete <ocrmirror filename>
eg:
# ocrconfig -delete +OCRVOTE2

After removal, the old OCR/OCRMIRROR can be deleted if they are on cluster filesystem.

3. To replace or move the location of an OCR device

10.2 and 11.1:
To replace the OCR device with <filename>, provide the full path including file name.

# ocrconfig -replace ocr <filename>
eg:
# ocrconfig -replace ocr /dev/sdd1
$ ocrconfig -replace ocr \\.\OCR2 - for Windows

To replace the OCR mirror device with <filename>, provide the full path including file name.

# ocrconfig -replace ocrmirror <filename>
eg:
# ocrconfig -replace ocrmirror /dev/raw/raw4
# ocrconfig -replace ocrmirror \\.\OCRMIRROR2  - for Windows

11.2:
The command is same for replace either OCR or OCRMIRRORs (at least 2 OCR exist for replace command to work):

4. To restore an OCR when clusterware is down

When OCR is not accessible, CRSD process will not start, hence the clusterware stack will not start completely. A restore of OCR device access and good OCR content is required.
To view the automatic OCR backup:

To restore the OCR backup:

For 11.2: If OCR is located in ASM disk and ASM disk is also lost, please check out:
How to restore ASM based OCR after complete loss of the CRS diskgroup on Linux/Unix systems Document 1062983.1
How to Restore OCR After the 1st ASM Diskgroup is Lost on Windows Document 1294915.1

If there is no valid backup of OCR presented, reinitialize OCR and Voting is required.
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.

ADD/DELETE/MOVE Voting Disk

For pre 11.2, to take a backup of voting disk:

$ dd if=voting_disk_name of=backup_file_name

For Windows:

ocopy \\.\votedsk1 o:\backup\votedsk1.bak

For 11.2+, it is no longer required to back up the voting disk. The voting disk data is automatically backed up in OCR as part of any configuration change. The voting disk files are backed up automatically by Oracle Clusterware if the contents of the files have changed in the following ways:

• Configuration parameters, for example misscount, have been added or modified

• After performing voting disk add or delete operations

The voting disk contents are restored from a backup automatically when a new voting disk is added or replaced.

For 10gR2 release

Shutdown the Oracle Clusterware (crsctl stop crs as root) on all nodes before making any modification to the voting disk. Determine the current voting disk location using:
crsctl query css votedisk

1. To add a Voting Disk, provide the full path including file name:

# crsctl add css votedisk <VOTEDISK_LOCATION> -force
eg:
# crsctl add css votedisk /dev/raw/raw1 -force
# crsctl add css votedisk /cluster_fs/votedisk.dat -force
> crsctl add css votedisk \\.\VOTEDSK2 -force   - for windows

2. To delete a Voting Disk, provide the full path including file name:

# crsctl delete css votedisk <VOTEDISK_LOCATION> -force
eg:
# crsctl delete css votedisk /dev/raw/raw1 -force
# crsctl delete css votedisk /cluster_fs/votedisk.dat -force
> crsctl delete css votedisk \\.\VOTEDSK1 -force   - for windows

3. To move a Voting Disk, provide the full path including file name, add a device first before deleting the old one:

# crsctl add css votedisk <NEW_LOCATION> -force
# crsctl delete css votedisk <OLD_LOCATION> -force
eg:
# crsctl add css votedisk /dev/raw/raw4 -force
# crsctl delete css votedisk /dev/raw/raw1 -force

After modifying the voting disk, start the Oracle Clusterware stack on all nodes

# crsctl start crs

Verify the voting disk location using

# crsctl query css votedisk

For 11gR1 release

Starting with 11.1.0.6, the below commands can be performed online (CRS is up and running).

1. To add a Voting Disk, provide the full path including file name:

2. To delete a Voting Disk, provide the full path including file name:

3. To move a Voting Disk, provide the full path including file name:

Verify the voting disk location:

For 11gR2 release

From 11.2, votedisk can be stored on either ASM diskgroup or cluster file systems. The following commands can only be executed when Grid Infrastructure is running. As grid user:

1. To add a Voting Disk
a. When votedisk is on cluster file system:

b. When votedisk is on ASM diskgroup, no add option available.
The number of votedisk is determined by the diskgroup redundancy. If more copies of votedisks are desired, one can move votedisk to a diskgroup with higher redundancy. See step 4.
If a votedisk is removed from a normal or high redundancy diskgroup for abnormal reason, it can be added back using:

 
2. To delete a Voting Disk
a. When votedisk is on cluster file system:

b. When votedisk is on ASM, no delete option available, one can only replace the existing votedisk group with another ASM diskgroup

3. To move a Voting Disk on cluster file system

4. To move voting disk on ASM from one diskgroup to another diskgroup due to redundancy change or disk location change

Example here is moving from external redundancy +OCRVOTE diskgroup to normal redundancy +CRS diskgroup

5. To move voting disk between ASM diskgroup and cluster file system
a. Move from ASM diskgroup to cluster file system:

b. Move from cluster file system to ASM diskgroup

6. To verify:

For Voting disk maintenance in Extended Cluster

Please refer to Oracle White paper: Oracle Clusterware 11g Release 2 (11.2) – Using standard NFS to support a third voting file for extended cluster configurations

If there is any issue using asmca tool, please refer to How to Manually Add NFS voting disk to an Extended Cluster using ASM in 11.2 Note 1421588.1 for detailed commands.