[Linux-cluster] NFS Server Cluster

[Wendy Cheng]

On Tue, 2006-05-23 at 17:35 -0500, Robert S Peterson wrote:
> On Tue, 2006-05-23 at 12:43 -0400, Mark Harrington wrote:
> > 3) Do we need to put /var/lib/nfs on a GFS volume so both NFS servers can
> > update the locks file?  Will there be any issues if both NFS servers try to
> > update the locks file at the same time?
> 
> I don't think so, but I could be wrong.

The current RHCS out in the fields have few locking issues that need to
get ironed out. The first visible problem is the existing Linux NLM
doesn't call filesystem specific lock method - implies GFS is not able
to support file locking via NFS across different servers. We're working
with NLM/NFS developers to solve these issues at this moment.

Don't confuse the issue with file locking across GFS nodes. File locking
(both flock and posix lock) across different GFS servers has been
supported.

Another specific is that we don't support NFS lock failover at this
moment. This is also due to some other Linux NLM issues and we're
working on it.


> > 3) Is it possible to do this with NFSv4?
> 

NFSv4 has state information that may not work well in a cluster
environment. It is again currently a work-in-progress effort. The CITI
group from University of Michigan is leading this development effort at
this moment. 


-- Wendy