Build Your Own Oracle RAC 10g Release 2 Cluster on Linux and FireWire
by Jeffrey Hunter - OTN

Install & Configure OCFS2 for Oracle RAC

Most of the configuration procedures in this section should be performed on all nodes in the cluster! Creating the OCFS2 filesystem, however, should be executed on only one node in the cluster.

It is now time to install OCFS2. OCFS2 is a cluster filesystem that allows all nodes in a cluster to concurrently access a device via the standard filesystem interface. This allows for easy management of applications that need to run across a cluster.

OCFS Release 1 was released in 2002 to enable Oracle RAC users to run the clustered database without having to deal with RAW devices. The filesystem was designed to store database related files, such as data files, control files, redo logs, archive logs, etc. OCFS2, in contrast, has been designed as a general-purpose cluster filesystem. With it, one can store not only database related files on a shared disk, but also store Oracle binaries and configuration files (shared Oracle Home) making management of RAC even easier.

In this guide, you will be using OCFS2 to store the two files that are required to be shared by the Oracle Clusterware software. (Along with these two files, you will also be using this space to store the shared SPFILE for all Oracle RAC instances.)

See this page for more information on OCFS2 (including Installation Notes) for Linux.

Download OCFS

First, download the OCFS2 distribution. The OCFS2 distribution comprises of two sets of RPMs; namely, the kernel module and the tools. The kernel module is available for download from http://oss.oracle.com/projects/ocfs2/files/ and the tools from http://oss.oracle.com/projects/ocfs2-tools/files/.

Download the appropriate RPMs starting with the key OCFS2 kernel module (the driver). From the three available kernel modules (below), download the one that matches the distribution, platform, kernel version and the kernel flavor (smp, hugemem, psmp, etc).

ocfs2-2.6.9-11.0.0.10.3.EL-1.0.4-1.i686.rpm - (for single processor)

or

ocfs2-2.6.9-11.0.0.10.3.ELsmp-1.0.4-1.i686.rpm - (for multiple processors)

or

ocfs2-2.6.9-11.0.0.10.3.ELhugemem-1.0.4-1.i686.rpm - (for hugemem)

For the tools, simply match the platform and distribution. You should download both the OCFS2 tools and the OCFS2 console applications.

ocfs2-tools-1.0.2-1.i386.rpm - (OCFS2 tools)
ocfs2console-1.0.2-1.i386.rpm - (OCFS2 console)

The OCFS2 Console is optional but highly recommended. The ocfs2console application requires e2fsprogs, glib2 2.2.3 or later, vte 0.11.10 or later, pygtk2 (EL4) or python-gtk (SLES9) 1.99.16 or later, python 2.3 or later and ocfs2-tools.

If you were curious as to which OCFS2 driver release you need, use the OCFS2 release that matches your kernel version. To determine your kernel release:

$ uname -a
Linux linux1 2.6.9-11.0.0.10.3.EL #1 Tue Jul 5 12:20:09 PDT 2005 i686 i686 i386 GNU/Linux

Install OCFS2

I will be installing the OCFS2 files onto two single-processor machines. The installation process is simply a matter of running the following command on all nodes in the cluster as the root user account:

$ su -
# rpm -Uvh ocfs2-2.6.9-11.0.0.10.3.EL-1.0.4-1.i686.rpm \
ocfs2console-1.0.2-1.i386.rpm \
ocfs2-tools-1.0.2-1.i386.rpm
Preparing... ########################################### [100%]
1:ocfs2-tools ########################################### [ 33%]
2:ocfs2-2.6.9-11.0.0.10.3########################################### [ 67%]
3:ocfs2console ########################################### [100%]

Disable SELinux (RHEL4 U2 Only)

RHEL4 U2 users (CentOS 4.2 is based on RHEL4 U2) are advised that OCFS2 currently does not work with SELinux enabled. If you are using RHEL4 U2 (which includes you, since you are using CentOS 4.2 here) you will need to disable SELinux (using tool system-config-securitylevel) to get the O2CB service to execute.

To disable SELinux, run the "Security Level Configuration" GUI utility:

# /usr/bin/system-config-securitylevel &