Topics: AIX, Oracle, SDD, Storage, System Admin

RAC OCR and VOTE LUNs

Consisting naming is nog required for Oracle ASM devices, but LUNs used for the OCR and VOTE functions of Oracle RAC environments must have the same device names on all RAC systems. If the names for the OCR and VOTE devices are different, create a new device for each of these functions, on each of the RAC nodes, as follows:

First, check the PVIDs of each disk that is to be used as an OCR or VOTE device on all the RAC nodes. For example, if you're setting up a RAC cluster consisting of 2 nodes, called node1 and node2, check the disks as follows: 

root@node1 # lspv | grep vpath | grep -i none
vpath6          00f69a11a2f620c5                    None
vpath7          00f69a11a2f622c8                    None
vpath8          00f69a11a2f624a7                    None
vpath13         00f69a11a2f62f1f                    None
vpath14         00f69a11a2f63212                    None

root@node2 /root # lspv | grep vpath | grep -i none
vpath4          00f69a11a2f620c5                    None
vpath5          00f69a11a2f622c8                    None
vpath6          00f69a11a2f624a7                    None
vpath9          00f69a11a2f62f1f                    None
vpath10         00f69a11a2f63212                    None
As you can see, vpath6 on node 1 is the same disk as vpath4 on node 2. You can determine this by looking at the PVID.

Check the major and minor numbers of each device: 
root@node1 # cd /dev
root@node1 # lspv|grep vpath|grep None|awk '{print $1}'|xargs ls -als
0 brw-------    1 root     system       47,  6 Apr 28 18:56 vpath6
0 brw-------    1 root     system       47,  7 Apr 28 18:56 vpath7
0 brw-------    1 root     system       47,  8 Apr 28 18:56 vpath8
0 brw-------    1 root     system       47, 13 Apr 28 18:56 vpath13
0 brw-------    1 root     system       47, 14 Apr 28 18:56 vpath14

root#node2 # cd /dev
root@node2 # lspv|grep vpath|grep None|awk '{print $1}'|xargs ls -als
0 brw-------    1 root     system       47,  4 Apr 29 13:33 vpath4
0 brw-------    1 root     system       47,  5 Apr 29 13:33 vpath5
0 brw-------    1 root     system       47,  6 Apr 29 13:33 vpath6
0 brw-------    1 root     system       47,  9 Apr 29 13:33 vpath9
0 brw-------    1 root     system       47, 10 Apr 29 13:33 vpath10
Now, on each node set up a consisting naming convention for the OCR and VOTE devices. For example, if you wish to set up 2 ORC and 3 VOTE devices:

On server node1: 
# mknod /dev/ocr_disk01 c 47 6
# mknod /dev/ocr_disk02 c 47 7
# mknod /dev/voting_disk01 c 47 8
# mknod /dev/voting_disk02 c 47 13
# mknod /dev/voting_disk03 c 47 14
On server node2: 
mknod /dev/ocr_disk01 c 47 4
mknod /dev/ocr_disk02 c 47 5
mknod /dev/voting_disk01 c 47 6
mknod /dev/voting_disk02 c 47 9
mknod /dev/voting_disk03 c 47 10
This will result in a consisting naming convention for the OCR and VOTE devices on bothe nodes: 
root@node1 # ls -als /dev/*_disk*
0 crw-r--r-- 1 root system  47,  6 May 13 07:18 /dev/ocr_disk01
0 crw-r--r-- 1 root system  47,  7 May 13 07:19 /dev/ocr_disk02
0 crw-r--r-- 1 root system  47,  8 May 13 07:19 /dev/voting_disk01
0 crw-r--r-- 1 root system  47, 13 May 13 07:19 /dev/voting_disk02
0 crw-r--r-- 1 root system  47, 14 May 13 07:20 /dev/voting_disk03

root@node2 # ls -als /dev/*_disk*
0 crw-r--r-- 1 root system  47,  4 May 13 07:20 /dev/ocr_disk01
0 crw-r--r-- 1 root system  47,  5 May 13 07:20 /dev/ocr_disk02
0 crw-r--r-- 1 root system  47,  6 May 13 07:21 /dev/voting_disk01
0 crw-r--r-- 1 root system  47,  9 May 13 07:21 /dev/voting_disk02
0 crw-r--r-- 1 root system  47, 10 May 13 07:21 /dev/voting_disk03




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