[Linux-cluster] NFS over GFS issue

[Abhijith Das]

Mark Hlawatschek wrote:
> Hi,
>
> During some stress tests with NFS over GFS, I observed a strange problem.
>
> The test setup consists of two GFS cluster nodes (node1, node2) (RHEL4.6), 
> both serving the same NFS exports (/mnt/gfstest)
> The NFS exports are mounted by two NFS clients (client1, client2), whereas 
> client1 has mounted the NFS export from node1 and client2 has mounted the NFS 
> export from node2.
>
> During the stress test, client1 creates files into dir1 on the GFS and client2 
> created files into dir2 on the same GFS. Node1 continuously reads the files 
> created by client1 and client2. After some time (about 10 minutes) the 
> following error occurs on node1:
>
> GFS: fsid=axqa01:gfstest.0: fatal: assertion "!bd->bd_pinned 
> && !buffer_busy(bh)" failed
> GFS: fsid=axqa01:gfstest.0:   function = ail_empty_gl
> GFS: fsid=axqa01:gfstest.0:   file 
> = /builddir/build/BUILD/gfs-kernel-2.6.9-75/smp/src/gfs/dio.c, line = 383
> GFS: fsid=axqa01:gfstest.0:   time = 1216216523
> GFS: fsid=axqa01:gfstest.0: about to withdraw from the cluster
> GFS: fsid=axqa01:gfstest.0: waiting for outstanding I/O
> GFS: fsid=axqa01:gfstest.0: telling LM to withdraw
> lock_dlm: withdraw abandoned memory
> GFS: fsid=axqa01:gfstest.0: withdrawn
>
> Is there a workaround for this problem ? Is this a bug ?
>
> Thanks,
>
> Mark
>
>   
This is a bug (https://bugzilla.redhat.com/show_bug.cgi?id=445000). We
were hitting this occasionally  in our testing, but not frequently
enough to help us debug it. I'm going to try your test case to see if I
can recreate the problem reliably.

Thanks!
--Abhi