[dm-devel] Re: [Linux-cluster] multipath/gfs lockout under heavy write

[David Teigland]

On Mon, Jan 24, 2005 at 08:57:28PM +0100, Lazar Obradovic wrote:
 
> Since both LVs are a part of same VG (and, thus, are using the same
> physical device seen over multipath), I'd guess the problem is somewhere
> inside GFS, but the things that keep confusing me are: 
> 
> - those SCSI errors that look like multipath errors

The SCSI errors appear to be the root problem, not GFS.  I don't know what
multipath might have to do with it.

> - name 'diapered_dm-2' which I never saw before

In the past, GFS would immediately panic the machine when it saw i/o
errors.  Now it tries to shut down the bad fs instead.  After this happens
you should be able to unmount the offending fs, leave the cluster and
reboot the machine cleanly.

> - fenced not fencing obviously faulty node

In your situation, the node is running fine wrt the cluster so there's no
need to fence it.  GFS is just shutting down a faulty fs (doing this is
not always very "clean" and can produce a lot of errors/warnings on the
console.)

Perhaps we could reinstate an option to have gfs panic immediately when it
sees i/o errors instead of trying to shut down the problem fs.  In this
case, the panicked node would be "dead" and it would be fenced.

-- 
Dave Teigland  <teigland at redhat.com>