From: Mark Watts <m.watts@eris.qinetiq.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: High CPU usage (up to server hang) under heavy I/O load
Date: Mon, 16 Aug 2004 13:10:14 +0100 [thread overview]
Message-ID: <200408161310.14300.m.watts@eris.qinetiq.com> (raw)
In-Reply-To: <1092653845.20528.3.camel@localhost.localdomain>
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
> On Llu, 2004-08-16 at 10:13, Mark Watts wrote:
> > Would this also mean that if I stick a 64bit SATA raid card (a 3Ware
> > 8506-4LP in this case) into a 32bit pci slot, then I/O is always going to
> > suck badly?
> >
> > ... cos I do, and I/O sucks :)
>
> Seperate issue.
>
> 64bit DMA is 64bit addressing (ie can DMA from above 4GB). 64bit wide
> slot is double the speed for transfers. The 3ware 8xxx I thought could
> do 64bit addressing although the driver seems to indicate it cannot,
> so with over 4Gb it would hurt.
We're running Dual Opterons (Tyan S2875 boards) with 2GB ram.
These boards only have 32bit pci slots so we're already not using the full
potential of the 3Ware.
Basically write performance is a major bottleneck (hardware raid-5 with 250GB
sata drives) and writing anything over a few meg usually causes the machine
to stall while the write occurs.
- --
Mark Watts
Senior Systems Engineer
QinetiQ Trusted Information Management
Trusted Solutions and Services group
GPG Public Key ID: 455420ED
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)
iD8DBQFBIKQmBn4EFUVUIO0RAjZ3AKDctamutj48XLKCMbY4FSfwgjtXEwCdGHPX
bvvd3PNk3SlilysaOYtwa6Y=
=rOlr
-----END PGP SIGNATURE-----
prev parent reply other threads:[~2004-08-16 12:11 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-13 14:01 High CPU usage (up to server hang) under heavy I/O load Sylvain COUTANT
2004-08-13 15:36 ` Matt Domsch
2004-08-13 15:46 ` Sylvain COUTANT
2004-08-14 3:39 ` Tom Sightler
2004-08-15 9:11 ` Lenar Lõhmus
2004-08-15 20:30 ` Sylvain COUTANT
2004-08-16 12:43 ` Matt Domsch
2004-08-13 16:20 ` Marcelo Tosatti
2004-08-13 17:53 ` Sylvain COUTANT
2004-08-16 10:11 ` Sylvain COUTANT
2004-08-16 11:49 ` Sylvain COUTANT
2004-08-13 22:16 ` Alan Cox
2004-08-16 9:13 ` Mark Watts
2004-08-16 10:57 ` Alan Cox
2004-08-16 12:10 ` Mark Watts [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=200408161310.14300.m.watts@eris.qinetiq.com \
--to=m.watts@eris.qinetiq.com \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox