ocfs2

While setting up ocfs2 for OCR and Voting disk storage with following commad:
# ocfs2console

After clicking on ==>cluster ==> configure nodes, I got a pop-up saying:

<span style="font-size: small;"><span style="font-family: arial,helvetica,sans-serif;">"Could not start cluster stack. This must be resolved before any OCFS2 filesystem can be mounted."</span></span>

Soon I realized that the thing which takes few minutes to get installed, is going to give me a tough time.

/var/log/messages shows following details:

<span style="font-size: small;"><span style="font-family: arial,helvetica,sans-serif;">Aug 17 14:53:40 rac1 modprobe: FATAL: Module configfs not found.
Aug 17 14:55:23 rac1 modprobe: FATAL: Module configfs not found.
Aug 17 14:56:56 rac1 modprobe: FATAL: Module configfs not found.
</span></span>

This prevents the configuration of OCFS2’s cluster stack, but it is mandatory to have OCFS2 cluster stack “O2CB” running, before
we can start anything with OCFS2 filesystem.

The stack includes the following services:

<span style="font-size: small;"><span style="font-family: arial,helvetica,sans-serif;">    * NM: Node Manager that keep track of all the nodes in the cluster.conf
    * HB: Heart beat service that issues up/down notifications when nodes join or leave the cluster
    * TCP: Handles communication between the nodes
    * DLM: Distributed lock manager that keeps track of all locks, its owners and status
    * CONFIGFS: User space driven configuration file system mounted at /config
    * DLMFS: User space interface to the kernel space DLM
</span></span>

“Error : modprobe: FATAL: Module configfs not found” can occur because of following reasons:

1. SELINUX is enabled.
2. Mismatch between the Kernel and OCFS2 module.

1. To check for selinux:
# sestatus
Or
# vi /etc/sysconfig/selinux

Make sure that selinux is DISABLED here.

2. To check for Mismatch:
# uname -a (It will give the exact kernel version of the OS)
2.6.9-42.ELsmp
# rpm -qa |grep ocfs2 (It will tell us the ocfs2 package currently installed)
ocfs2-2.6.9-89.EL

Here it can be seen that ocfs2 is for kernel version 89 not for kernel version 42.

So I downloaded the correct OCFS2 kernel modules from:
http://oss.oracle.com/projects/ocfs2/files/
and the tools from
http://oss.oracle.com/projects/ocfs2-tools/files/

After installing the correct module and disabling the selinux settings, I got the cluster stack running.