[Ocfs2-users] Soft and Hard Readonly?

[Mark Fasheh]

On Mon, Nov 13, 2006 at 01:38:57PM -0800, Sunil Mushran wrote:
> To mount readonly, do:
> mount -o ro /dev/sdX /dir
> 
> The difference between soft and hard is that in the latter the heartbeat 
> is not
> started. Meaning no need to join a dlm domain. The latter only works on
> actual readonly devices.
To add to Sunil's description, you probably want to use soft readonly on
your cluster. To the application the file system will not allow writes, but
the ocfs2 stack will still join the dlm domain, heartbeat, etc. This allows
the nodes to perform recovery in case of failure and retain data / meta
consistency behaviors.

Mounting 'ro' gives you soft readonly unless you mount on a disk that is not
writeable, in which case the file system falls back to "hard readonly".
	--Mark

--
Mark Fasheh
Senior Software Developer, Oracle
mark.fasheh at oracle.com