Oracle provides the file system OCFS2 to support Oracle RAC file storage. This file system provides for a locking mechanism which allows files to be accessed by multiple Oracle instances while avoiding corruption. The OSFS2 file system binaries must be started before any OCFS2 formatted mount points can be accessed. This article shows the error generated when the OCFS2 stack has not been started and how to resolve the problem.

General OS error:

[root@mylinux init.d]# mount /dev/mapper/MPATH10 /u02
mount.ocfs2: Unable to access cluster service while trying initialize cluster

Resolution:

1. Logon to your server as root.
2. Change directory to /etc/init.d

[root@mylinux /]# cd /etc/init.d
[root@mylinux init.d]# pwd
/etc/init.d
[root@mylinux init.d]#

3. Execute the OS layer command ./ocfs2 load.

[root@mylinux init.d]# ./o2cb load
Loading filesystem “configfs”: OK
Mounting configfs filesystem at /sys/kernel/config: OK
Loading filesystem “ocfs2_dlmfs”: OK
Mounting ocfs2_dlmfs filesystem at /dlm: OK
[root@mylinux init.d]#

4. Execute the OS layer command ./ocfs2 online

[root@mylinux init.d]# ./o2cb online
Starting O2CB cluster ocfs2: OK
[root@mylinux init.d]#

5. Attempt to mount your ocfs2 storage device.

[root@mylinux init.d]# mount /dev/mapper/MPATH10 /u02
[root@mylinux init.d]#

6. This completes restarting OCFS2 binaries.

Larry J. Catt, OCP 9i, 10g
oracle@allcompute.com
www.allcompute.com