NFS Locking Issue

[Chuck Swiger]

Michel Talon wrote:
[ ...a long email snipped... ]
> My only conclusion is that these NFS stories are very
> tricky. The only moment everything worked fine was when we were running
> Solaris on the server.

I can't speak to the earlier part about NFS with Linux, but at least I very 
much agree with your conclusion: Solaris makes one of the best NFS servers 
available, over a broad range of use cases.

However, I also wish to note that if you want to use NFS and you need remote 
locking to work, your best hope is when the software you use is willing to use 
explicit lockfiles rather than depending on rpc.lockd to provide remote 
flock()/lockf()-style locking.

There are plenty of software out there which includes locking tests (sendmail 
does, UWash IMAP does, Perl does, etc), and my observation has been that 
actually using NFS-based remote locking under anything beyond trivial load 
tends to make rpc.lockd terminate within seconds (maybe with a core dump, if 
you get lucky), or end up with processes getting stuck forever waiting on 
locks that don't ever return because they've been lost somewhere in limbo.

YMMV.  :-)

-- 
-Chuck