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From: "Mathias Burén" <mathias.buren@gmail.com>
To: Emmanuel Noobadmin <centos.admin@gmail.com>
Cc: CentOS mailing list <centos@centos.org>,
	linux-raid <linux-raid@vger.kernel.org>
Subject: Re: Possible to use multiple disk to bypass I/O wait?
Date: Thu, 9 Jun 2011 11:19:39 +0100	[thread overview]
Message-ID: <BANLkTikd-LEtAt_3n6bC7nTd2BZqZfNQLA@mail.gmail.com> (raw)
In-Reply-To: <BANLkTimFOaJoMnwid1F+ghVwkBgJi2FymQ@mail.gmail.com>

On 9 June 2011 10:24, Emmanuel Noobadmin <centos.admin@gmail.com> wrote:
> I'm trying to resolve an I/O problem on a CentOS 5.6 server. The
> process basically scans through Maildirs, checking for space usage and
> quota. Because there are hundred odd user folders and several 10s of
> thousands of small files, this sends the I/O wait % way high. The
> server hits a very high load level and stops responding to other
> requests until the crawl is done.
>
> I am wondering if I add another disk and symlink the sub-directories
> to that, would that free up the server to respond to other requests
> despite the wait on that disk?
>
> Alternatively, if I mdraid mirror the existing disk, would md be smart
> enough to read using the other disk while the first's tied up with the
> first process?
> --
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>

The first thing that comes to my mind: Have you tried another IO scheduler?

/M
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  reply	other threads:[~2011-06-09 10:19 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-09  9:24 Possible to use multiple disk to bypass I/O wait? Emmanuel Noobadmin
2011-06-09 10:19 ` Mathias Burén [this message]
2011-06-09 16:15   ` Emmanuel Noobadmin
2011-06-09 12:06 ` Nagilum
     [not found] ` <BANLkTimFOaJoMnwid1F+ghVwkBgJi2FymQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2011-06-09 19:06   ` Steve Thompson

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