[Cluster-devel] NFS v2 not compatible with GFS2

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

On Tue, 2009-04-07 at 13:04 -0700, Craig Johnston wrote:
> We have found that NFS version 2 does not seem to be compatible with
> an NFS exported GFS2 file system.  The NFS client can mount the file
> system, but any file I/O results in Stale File Handle and I/O errors.
> 
> It looks very much like the problem described here -
> https://bugzilla.redhat.com/show_bug.cgi?id=229345
> 
> Has there been any progress on resolving this issue, or are we out of
> luck.  We have a legacy device that will only use NFS v2, and we would
> very much like to use GFS2 as we do for the rest of our system.
> 
> To replicate the problem for a GFS2 exported file system (say
> /data/mygfs2_fs on host foo ), mount it on another host as
> "% mount -o nfsvers=2 foo:/data/mygfs2_fs /mnt/tmp"
> 
> You will find that you can list the directory entries, but any attempt
> to read or write to files will fail.
> 
> Note, we find that the GFS file system does not seem to have problems
> with NFS v2 clients, only GFS2.
> 
> Any help would be appreciated.
> Craig
> 
Yes, it is a bug inherited from GFS. GFS2 uses the same filehandles
(i.e. too large for NFSv2) so that for the time being, only NFSv3+ will
work with GFS2. I don't know why GFS appears to work and GFS2 doesn't -
they should be identical in that respect,

Steve.