OT: Packet Filtering to Relieve Server Congestion?

[Bill Perkins]

Hugh Caley wrote:
> We're running FC2 on a couple of servers connected to a Nexsan
> atabeast.  NFS access to the servers is great, until our 200+ node
> cluster fires up and swamps us.
> 
> I was wondering what people have used as solutions for this problem.  I
> don't really have to serve the cluster much faster, but I do have to
> keep non-cluster interactive unix sessions going in decent real time.
> 
> Could I do something like use packet filtering and queueing on the NFS
> servers to make certain that packets from machines other than the
> cluster get first priority?  The cluster nodes are on designated
> subnets; could I have the server put everything else first, or maybe
> reserve 3/4 of the bandwidth for the cluster so that other things don't
> slow down too much?
> 
> Could I do this sort of thing on the servers themselves, or would there
> have to be another machine in front of them?
> 
> We are currently running 256 nfsds on each server, which maybe helped a
> little bit over the default 8 nfsds.
> 
> Hugh
> 

There are all kinds of things you can do here. I would put the servers 
and the cluster onto a switch or something, and run that into a separate 
NIC (network interface card) on your servers, and have a 2nd NIC for 
your other users, for starters. Also, I would dedicate a separate 
IDE/SCSI/whatever controller for the NFS drives; can you separate the 
cluster's NFS directories from the regular users?

-- 
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"The two most common things in the	| Bill Perkins
  universe are Hydrogen and Stupidity."	| perk at iag.net
					| programmer-at-large
		F. Zappa		| ALL assembly languages done here.
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