Ocfs2 devel - Dec 2010 - [PATCH] Call userspace script when self-fencing

Hi,

According to comments in file fs/ocfs2/cluster/quorum.c:70 about the  
self-fencing operations :

/* It should instead flip the file
?* system RO and call some userspace script. */

So, I tried to add it (but i did'nt find a way to flip the fs in RO).

Here is a proposal for this functionnality, based on ocfs2-1.4.7.
This patch add an entry 'fence_cmd' in /sys to specify an userspace  
fence script.
This behavior can be selected by echoing the new keyword 'cmd' in  
fence_method.

Example :

echo "/usr/local/sbin/my_fencer">
/sys/kernel/config/cluster/ocfs2/fence_cmd
echo "cmd"> /sys/kernel/config/cluster/ocfs2/fence_method

Hope this could interest someone.

   Nicolas AGIUS

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Is it safe to call usermode_helper from an interrupt context?

Even if it is safe, we cannot do this because we cannot rely on an
external script. Any delay and either the cluster hangs or worse,
corruption.

If you want to use external fencing, then my suggestion would be
to look at latest fedora, opensuse, ubuntu, debian or sles11 which
bundle ocfs2 and the pacemaker cluster stack. You can then configure
ocfs2 to use the pcmk stack and make use of its different fencing
agents.

On 12/09/2010 01:11 AM, nagius at astek.fr wrote:
>
> Hi,
>
> According to comments in file fs/ocfs2/cluster/quorum.c:70 about the
self-fencing operations :
>
> /* It should instead flip the file
>  * system RO and call some userspace script. */
>
> So, I tried to add it (but i did'nt find a way to flip the fs in RO).
>
> Here is a proposal for this functionnality, based on ocfs2-1.4.7.
> This patch add an entry 'fence_cmd' in /sys to specify an userspace
fence script.
> This behavior can be selected by echoing the new keyword 'cmd' in
fence_method.
>
> Example :
>
> echo "/usr/local/sbin/my_fencer">
/sys/kernel/config/cluster/ocfs2/fence_cmd
> echo "cmd"> /sys/kernel/config/cluster/ocfs2/fence_method
>
>
> Hope this could interest someone.
>
> Nicolas AGIUS
>
>
>
> ----------------------------------------------------------------
> This message was sent using IMP, the Internet Messaging Program.
>
>
> _______________________________________________
> Ocfs2-devel mailing list
> Ocfs2-devel at oss.oracle.com
> http://oss.oracle.com/mailman/listinfo/ocfs2-devel
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