How to Configure Oracle RAC OCR & Voting Disks

Information about How To Configure Oracle RAC OCR & Voting Disks

This document will explain how to configure rawdevices from the SAN and how they should be setup as  Oracle RAC OCR and Voting Disks

Document Creator

Todd Walters

 Requirements

• Make sure you've performed Oracle RAC Post Install for physical/virtual servers.
• Prepare Linux Virtual Servers for Oracle RAC
• Prepare Linux Physical Servers for Oracle RAC
• Oracle RAC is installed on csrv0dbx01, csrv0dbx02, and csrv0dbx03
• The name of the database is psitedb
• The rawdevices are on EMC SAN
• /etc/sysconfig/rawdevices file must be edited on all nodes
• Voting disk are raw1, raw2, and raw3
• OCR Disks are raw4 and raw5

How to Configure Oracle RAC OCR and Voting Disks 

1. Login to Oracle Server (node 1 for example, csrv0dbx01)
2. su -
3. cd /etc/sysconfig/and edit with vi, the 'rawdevices'  file to match below.
   # Voting Disks
   /dev/raw/raw1   /dev/emcpowera
   /dev/raw/raw2   /dev/emcpowerb
   /dev/raw/raw3   /dev/emcpowerc
   # OCR disks
   /dev/raw/raw4   /dev/emcpowerd
   /dev/raw/raw5   /dev/emcpowere
4. Start rawdevices:
   
   [root@csrv0dbx03 sysconfig]# service rawdevices startAssigning devices:
   Assigning devices:
              /dev/raw/raw1  -->   /dev/emcpowera
   /dev/raw/raw1:  bound to major 120, minor 0
              /dev/raw/raw2  -->   /dev/emcpowerb
   /dev/raw/raw2:  bound to major 120, minor 16
              /dev/raw/raw3  -->   /dev/emcpowerc
   /dev/raw/raw3:  bound to major 120, minor 32
              /dev/raw/raw4  -->   /dev/emcpowerd
   /dev/raw/raw4:  bound to major 120, minor 48
              /dev/raw/raw5  -->   /dev/emcpowere
   /dev/raw/raw5:  bound to major 120, minor 64
   done
5. Check Status of raw devices

[root@csrv0dbx03 sysconfig]# service rawdevices status

/dev/raw/raw1:  bound to major 120, minor 0

/dev/raw/raw2:  bound to major 120, minor 16

/dev/raw/raw3:  bound to major 120, minor 32

/dev/raw/raw4:  bound to major 120, minor 48

/dev/raw/raw5:  bound to major 120, minor 64

6. Verify rawdevices is set to start at boot time.
   
   [root@csrv0dbx02 sysconfig]# chkconfig --list rawdevices
   rawdevices      0:off   1:off   2:on    3:on    4:on    5:on    6:off

There are two different values for the permissions of the OCR and Voting devices.

1. One is for the pre-installation, and the other is for post installation.
2. The install process of the CRS software changes the device permissions.

The pre-install values are :

* note: Check that permissions and ownership is set as displayed below before installing CRS.

CRS Component	Raw Device	Size	Ownership	Privilege
Voting 1	/dev/raw/raw1	140 mb	oracle:dba	660
Voting 2	/dev/raw/raw2	140 mb	oracle:dba	660
Voting 3	/dev/raw/raw3	140 mb	oracle:dba	660
OCR 1	/dev/raw/raw4	140 mb	root:dba	660
OCR 2	/dev/raw/raw5	140 mb	root:dba	660

The post install values are:

Note: These values should be set in /etc/udev/permissions.d/50-udev.permissions

(This will ensure that the permissions are reset after a system reboot)

CRS Component	Raw Device	Size	Ownership	Privilege
Voting 1	/dev/raw/raw1	140 mb	oracle:dba	0664
Voting 2	/dev/raw/raw2	140 mb	oracle:dba	0664
Voting 3	/dev/raw/raw3	140 mb	oracle:dba	0664
OCR 1	/dev/raw/raw4	140 mb	root:dba	0660
OCR 2	/dev/raw/raw5	140 mb	root:dba	0660

Example 50-udev.permissions file from csrv0dbx01

# Oracle with ASMlib
emcpower*:oracle:dba:0770
# Voting
raw/raw1:oracle:dba:0664
raw/raw2:oracle:dba:0664
raw/raw3:oracle:dba:0664
# OCR
raw/raw4:root:dba:0660
raw/raw5:root:dba:0660
# 

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