From: "Miquel van Smoorenburg" <miquels@cistron.nl>
Subject: Re: High write latency, iowait, slow writes 2.6.9
Date: Wed, 12 Jan 2005 21:20:18 +0000 (UTC)
Organization: Cistron Group
Message-ID: <cs44ai$oet$1@news.cistron.nl>
References: <41E4BB99.90908@zanfx.com>
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Originator: miquels@cistron-office.nl (Miquel van Smoorenburg)
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In article <41E4BB99.90908@zanfx.com>,
Paul A. Sumner <paul@zanfx.com> wrote:
>I have a new server that during big io tasks, e.g., bonnie++ and
>tiobench testing, becomes very unresponsive. Both bonnie++ and tiobench
>show good read performance, but the write performance lags, max
>latencies are into the *minutes* and it experiences extended high
>iowait. I'm guessing the iowait may not be a real problem. The machine
>is as follows:

Try another IO scheduler (boot with elevator=deadline or elevator=cfq
 on the kernel command line)

Mike.

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