When running ocfs2 on cLVM, openais+pacemaker setup, you may run into something like described below.

The symptoms:

umount /data1
mspx1d0:~ # tunefs.ocfs2 –fs-features=sparse,unwritten /dev/system/data1
tunefs.ocfs2: Unable to access cluster service while opening device “/dev/system/data1”
mspx1d0:~ # mount /dev/system/data1 /data1
mspx1d0:~ # tunefs.ocfs2 –fs-features=sparse,unwritten /dev/system/data1
tunefs.ocfs2: Configuration error discovered while opening device “/dev/system/data1”

Here is how to get past cluster check when running ocfs2-tools.

From hb_gui or crm stop mounting of the file system and ocf::ocfs2:o2cb resources.

Install ocfs2-tools-o2cb package

Do normal stack configuration using /etc/init.d/o2cb configure, but do not auto start on boot. Read the fine ocfs2 manual.

Bring ocfs2 online: /etc/init.d/o2cb online ocfs2

Start ocfs2 service: rcocfs2 start

Update cluster stack on your partition with ocfs2 filesystem: tunefs.ocfs2 –update-cluster-stack /dev/system/data1

Do your thing with ocfs2-tools, such as: tunefs.ocfs2 -v –fs-features=sparse,unwritten /dev/system/data1

Stop ocfs2 service and unload o2cb: rcocfs2 stop && /etc/init.d/o2cb offline ocfs2 && /etc/init.d/o2cb unload

Re-enable ocf::ocfs2:o2cb resources and run tunefs.ocfs2 –update-cluster-stack /dev/system/data1 again. Re-enable mounting from hb_gui.  Hope there is a simpler way somewhere that I am not aware of.