Hi .. Besides MP hangs I've experienced, another that I've run into
that just about everyone else has is NFS hangs.  Maybe this one could
be quick and easy to sort out.

I have a few questions ..

1) Would an NFS server running on a machine built on 1.5.2 (w/ a 1.5.4 kernel)
   have compatibility issues with a client running 1.6?

2) How do you decide how many severs to spawn?  number of exported filesystems
   or number of clients?

3) are there any parameters that can be tweaked?  I know of vfs.nfs.iothreads
   (should this correspond to the number of nfsd servers running?)

4) On the client side, I'm not sure if this is documented clearly, but how
   can the options in mount_nfs be used?  (fstab's manpage gives no
   clues)  If these are setable somewhere, I would guess thats why setting
   the server to only -t would cause the clients to scratch their heads 
   (default behaviour is to use UDP). 


   fstab options?  rw,-D5,-T,-b,-i,-r=8192,-w-8192

The problem I'm seeing is sometimes an NFS server will not be responding
and then come back .. sometimes the 1.6 client hangs after 3 or so days
of uptime while the 1.5.x client keeps going .. sometimes I see nfsd send
error 55 on the server.. many times I see
nfs server sdf1:/sys: not responding
nfs server sdf1:/sys: is alive again
uvn_attach: blocked at 0x0xfffffc0020b41ba8 flags 0x4
uvn_attach: blocked at 0x0xfffffc000b926de0 flags 0x4

NFS data in my configuration uses a private 100mbit switched lan.