From: Trond Myklebust <trond.myklebust@fys.uio.no>
Subject: Re: Client performance questions
Date: Mon, 10 Dec 2007 18:10:26 -0500
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Cc: "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
To: Fredrik Lindgren <fli-FpffG6+3qsA@public.gmane.org>
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On Mon, 2007-12-10 at 22:52 +0100, Fredrik Lindgren wrote:
> Hello
> 
> We have a mail-application running on a set of Linux machines using NFS
> for the storage. Recently iowait on the machines has started to become
> a problem, and it seems that they can't quite keep up. Iowait figures of
> 50% or above are not uncommon during peak hours.

Have you tried increasing the value
in /proc/sys/fs/nfs/nfs_congestion_kb ?

Cheers
  Trond