Voting disk and OCR Management

The recommendations for the addition or removal of a voting disk is shutdown Oracle Cluster ware first on all nodes and then utilize the commands below as root user where path is completely qualified path for the additional voting disk. In the case of new voting disk over the network file system (NFS), create an empty voting disk file location with the correct owner and permissions before execute of commands mentioned below. Three extra raw partitions /dev/raw/raw3/, dev/raw/raw4, /dev/raw/raw5 have been created in order to practice following excercises

• Run the following command to find path of voting disks

[oracle@crs1 ~]$ crsctl query css votedisk

0. 0 /dev/raw/raw2

located 1 votedisk(s).

• Run the following command as the root user to add a voting disk

[root@crs1 oracle]# crsctl stop crs

[root@crs2 oracle]# crsctl stop crs

[root@crs1 oracle]# crsctl add css votedisk /dev/raw/raw3 -force

Now formatting voting disk: /dev/raw/raw3

successful addition of votedisk /dev/raw/raw3.

[root@crs1 oracle]# crsctl start crs

[root@crs2 oracle]# crsctl start crs

[oracle@crs2 oracle]$ crsctl query css votedisk

0. 0 /dev/raw/raw2

1. 0 /dev/raw/raw3

located 2 votedisk(s).

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

# crsctl delete css votedisk path

• Backup and Recovery of Voting Disk

Back up the voting

dd if=voting_disk_name of=backup_file_name

[oracle@crs1 ~]$ dd if=/dev/raw/raw2 of=/home/oracle/backup/votdisk1

Recovering Voting Disks

dd if=backup_file_name of=voting_disk_name

• Administering the Oracle Cluster Registry in Oracle Real Application Clusters

OCR file location is in following file

For Sun Solaris /var/opt/oracle/ocr.loc

For Linux /etc/oracle/ocr.loc

If OCR resides on a cluster, file system file or if the OCR is on a network file system, then create the target OCR file before adding OCR.

• Use the OCRCHECK utility to verify the OCR integrity

The things displayed by OCRCHECK utility are – the version of the OCR’s block format; total space used and available; OCRID; and the OCR locations that have been configured. A block-by-block checksum operation for all of the blocks in all the configured OCRs is performed by OCRCHECK. It also returns an individual status for each file as well as a result for the overall OCR integrity check.

[root@crs1 oracle]# ocrcheck

Status of Oracle Cluster Registry is as follows :

Version : 2

Total space (kbytes) : 524184

Used space (kbytes) : 5644

Available space (kbytes) : 518540

ID : 87847809

Device/File Name : /dev/raw/raw1

Device/File integrity check succeeded

Device/File not configured

Cluster registry integrity check succeeded

Device/File not configured means ocrmirror is not configured

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.

• Run the following command to add an OCR mirror location using either destination_file or disk to designate the target location of the additional OCR

First, make sure you have proper backup of ocr

[root@crs2 oracle]# ocrconfig –showbackup

• Run the following command to add an OCR location using either destination_file or disk to designate the target location of the additional OCR

ocrconfig -replace ocr destination_file or disk

ocrconfig -replace ocrmirror destination_file or disk

First zero out the raw device

If your OCR configuration were altered while a particular node is stopped, you would be required to repair the OCR configuration on that particular node. For instance, there may be need to repair the OCR on a node that was not up at the time of removing, replacing or adding an OCR. For repairing an OCR configuration, run the following command on the node on which the Oracle Clusterware daemon was stopped.

ocrconfig –repair ocrmirror device_name

This operation only changes the OCR configuration on the node from which you run this command. For example, if the OCR mirror device name is /dev/raw1, then use the command syntax ocrconfig -repair ocrmirror /dev/raw1 on this node to repair its OCR configuration.

You cannot perform this operation on a node on which the Oracle Clusterware daemon is running.

• Run the following command on any node in the cluster to remove the OCR

ocrconfig -replace ocr

• Run the following command on any node in the cluster to remove the mirrored OCR

ocrconfig -replace ocrmirror

• The above commands update the OCR configuration on all of the nodes on which Oracle Clusterware is running.
• The ocrconfig Command Options

Option	Purpose
-backuploc	To change an OCR backup file location. For this entry , use a full path that is accessible by all of the nodes.
-downgrade	To downgrade an OCR to an earlier version.
-export	To export the contents of an OCR into a target file.
-help	To display help for the ocrconfig commands.
-import	To import the OCR contents from a previously exported OCR file.
-overwrite	To update an OCR configuration that is recorded on the OCR with the current OCR configuration information that is found on the node from which you are running this command.
-repair	To update an OCR configuration on the node from which you are running this command with the new configuration information specified by this command.
-replace	To add, replace, or remove an OCR location.
-restore	To restore an OCR from an automatically created OCR backup file.
showbackup	To display the location, timestamp, and the originating node name of the backup files that Oracle created in the past 4 hours, 8 hours, 12 hours, and in the last day and week. You do not have to be the root user to execute the -showbackup option.
-upgrade	To upgrade an OCR to a later version.

For example, to export the OCR contents to a binary file, use the ocrconfig command with the following syntax where file_name is the file to which you want to export the OCR contents as follows

ocrconfig -export file_name

• Managing Backups and Recovering the OCR Using OCR Backup Files

This section explains the two methods for the purpose of copying of OCR content and further utilizing it for recovery. The first method uses automatically generated OCR file copies and the second method uses manually created OCR export files.

The Oracle Clusterware automatically creates OCR backups every four hours. At any one time, Oracle always retains the last three backup copies of the OCR. The CRSD process that creates the backups also creates and retains an OCR backup for each full day and at the end of each week.

Restoring the Oracle Cluster Registry on UNIX-Based Systems: use oracheck to check OCR status

Use the following procedure to restore the OCR on UNIX-based systems:

Identify the OCR backups using the ocrconfig -showbackup command. Review the contents of the backup using ocrdump -backupfile file_name where file_name is the name of the backup file.

Stop Oracle Clusterware on all of the nodes in your Oracle RAC database by executing the init.crs stop command on all of the nodes.

Perform the restore by applying an OCR backup file that you identified in Step 1 using the following command where file_name is the name of the OCR that you want to restore. Make sure that the OCR devices that you specify in the OCR configuration exist and that these OCR devices are valid before running this command.

ocrconfig -restore file_name

Restart Oracle Clusterware on all of the nodes in your cluster by restarting each node or by running the init.crs start command.

Run the following command to verify the OCR integrity where the -n all argument retrieves a listing of all of the cluster nodes that are configured as part of your cluster.

cluvfy comp ocr -n all [-verbose]

Use the OCRDUMP utility to write the OCR contents to a file so that you can examine the OCR content.

ocrdump [file_name|-stdout] [-backupfile backup_file_name] [-keyname keyname] [-xml] [-noheader]

OCRDUMP Options and Option Descriptions

Options	Description
file_name	Name of a file to which you want OCRDUMP to write output.
-stdout	The predefined output location that you can redirect with, for example, a filename.
-keyname	The name of an OCR key whose subtree is to be dumped.
-xml	Writes the output in XML format.
-noheader	Does not print the time at which you ran the command and when the OCR configuration occurred.
-backupfile	Option to identify a backup file.
backup_file_name	The name of the backup file the content of which you want to view. You can query the backups using the ocrconfig -showbackup command

• OCR Exports/Imports

ocrconfig -export file_name

ocrconfig -import file_name

Restart Oracle Clusterware on all of the nodes in your cluster by restarting each node.

Run the following Cluster Verification Utility (CVU) command to verify the OCR integrity where the -n all argument retrieves a listing of all of the cluster nodes that are configured as part of your cluster:

cluvfy comp ocr -n all [-verbose]