Hi,

On Fri, Jun 04, 2010 at 02:16:42PM +0200, Bernd Schubert wrote:
> On Friday 04 June 2010, Dejan Muhamedagic wrote:
> > Hi Takatoshi-san,
> > 
> > On Fri, Jun 04, 2010 at 02:19:42PM +0900, Takatoshi MATSUO wrote:
> > > Hello
> > >
> > > I suggest to add a parameter which decides executing fsck
> > > as user's policy in Filesystem RA.
> > >
> > > Because, current RA dose not check ext3 because executing fsck depends on
> > > filesystem.
> > > But ext3 sometimes is broken and remounted read-only although it has
> > > journal, so
> > 
> > Under which circumstances does this happen?
> 
> No filesystem is perfect ;) And any kind of hardware issue can cause 
> filesystem and data corruption. 

Filesystem corruption? That's like not what I exactly had in mind :)
I'm not sure if fsck would help in that case anyway. Not saying
that that never happens (hw or bugs), but what I meant is
"normal" (say, on stonith) failovers where no fs corruption occurs.

> Takatoshi-san, you should notice however, that for example e2fsck will start 
> to run in non-auto mode, even if only a journal recovery is required. With 
> default extX paramters, it then easily might perform a complete filesystem 
> check, which might last hours. Not only that you might get unexpected long 
> down time, you also need to be aware, that fsck time is often MUCH longer 
> than 
> the resource start timeout. If that happens, pacemaker will kill fsck in the 
> middle of a run, which might damage your filesystem even more.
> 
> That is all fine if you know about possible consequences, but I really doubt 
> that most admins are aware of that.

Most admins are not aware of most things ;-)

> > > I want to decide myself executing fsck before mount to operate more
> > > safely.
> > >
> > > This new parameter has three mode "auto","force" and "no".
> > > Default is "auto" which do the same thing as before.
> > > "force" and "no" mean what they say.
> > 
> > Patch applied. Many thanks!
> 
> That brings up and idea here, with extX, we could easily use 
> 
> dumpe2fs -h | grep "Filesystem state:" 
> 
> to check if fsck needs to be run. So the agent could refuse to mount the 
> decide and make you run it manually in the foreground without any timeouts...
> I will implement that for our lustre_server agent (a heavily modified 
> Filesystem agent) and then possibly back-port the patch.

That may be a good idea. Given that one can say how long would
e2fsck take.

Cheers,

Dejan

> Cheers,
> Bernd
> 
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