Is NFS Locking Reliable?

[Konrad Heuer]

I'd like to ask for your experiences with NFS locking in larger 
environments.

Our experiences are not so satisfying. Our NFS servers for user home 
directories are on FreeBSD (6.4), MacOSX (10.5), Linux (still 2.4 kernel) 
and Tru64-UNIX boxes; NFS clients are mostly Linux (2.6 kernel) and 
FreeBSD (6.4, 7.0, but w/o kernel lockd) systems.

There are periods of several days without problems, but from time to time, 
on one, two, or several (but not all) clients application processes which 
use locking suddenly hang in kernel mode - namely firefox, opera, pine.

It seems to be no specific operating system problem - all combinations of 
clients and servers are involved.

There are some suspicious facts that out network may cause problems 
although not all ip subnets are protected by cisco firewall modules. But 
there may be other circumstances which could lead to sporadic packet 
losses or whatever else ...

So, if anyone has similar or other experiences with NFS locking, I'm very 
interested in reading about!

Thank you very much in advance!

Konrad Heuer
GWDG, Am Fassberg, 37077 Goettingen, Germany, kheuer2 at gwdg.de