[Beowulf] max number of NFS threads: NFS config optimization

[Rahul Nabar]

For a while I've been seeing errors of this sort in my /var/log/messages

kernel: nfsd: too many open TCP sockets, consider increasing the number of
nfsd threads

I googled a bunch and think the solution might be to boost RPCNFSDCOUNT in
the line "[ -z "$RPCNFSDCOUNT" ] && RPCNFSDCOUNT=8"  in the file
/etc/init.d/nfs.

Question: This seems a suspicious place to change it. Isn't there a nfs
config file somewhere else?

Question2: How high can I boost the number of NFS threads? Or how I should
I? Is there any metric I can track to decide an optimum number? Most
recomendations were for 32, 64 or 128. What do people suggest? Any
downsides to having numbers that are too high?

In case it matters, this is our master-node Linux server and has the
/home directories for each user
exported to about 200 odd compute-nodes.

-- 
Rahul