From: Illtud Daniel <illtud.daniel@llgc.org.uk>
To: raid-list <linux-raid@vger.kernel.org>
Subject: Re: about the speed
Date: Wed, 02 Apr 2003 10:58:29 +0100 [thread overview]
Message-ID: <3E8AB445.A76ED9D6@llgc.org.uk> (raw)
In-Reply-To: 3E87FC9D.5010605@bnap.hu
Farkas Levente wrote:
> I'm just read
> http://www.hpl.hp.com/techreports/2002/HPL-2002-352.pdf
> may be it's worth to read. an intersting thing about performance (XP,
> their user-space raid and than comes kernel raid).
Any comments from md developers? This is from the abstract:
The paper contains preliminary results from an investigation comparing
Linux and WindowsXP disk I/O using kernel-based software RAID on
identical hardware. WindowsXP performance is shown to be substantially
superior to Linux performance, for reasons not currently understood.
And the meat of the report:
5.5. Direct comparison
Of crucial interest is the direct comparison between WindowsXP,
the kernel-based Linux software RAID implementation, and the
userlevel software RAID implementation.
From Figure 8 it can be seen that csraid generally outperforms
the kernel-based RAID driver, and its performance is far more
stable, particularly for large requests. Also, the WindowsXP
RAID driver is astonishingly good, even compared to JBOD, with
JBOD’s performing better for request sizes smaller than 4MB
and WindowsXP performing better at the larger sizes.
csraid’s performance is generally less than WindowsXP, but
overall the loss is not catastrophic, and is likely
sufficient for the most purposes.
Figure 8 shows that XP's RAID can be 60+% faster than md at
writing, and up to 100% faster at reading (at request size
7MB, which is rather a blip). Any inital thoughts on this report?
Has the performance changed substantially since? The distro was
Mandrake 8.2, the kernel 2.4.18-6mdk. Any comments on the
methodology or conclusions?
--
Illtud Daniel illtud.daniel@llgc.org.uk
Uwch Ddadansoddwr Systemau Senior Systems Analyst
Llyfrgell Genedlaethol Cymru National Library of Wales
Yn siarad drosof fy hun, nid LlGC - Speaking personally, not for NLW
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next prev parent reply other threads:[~2003-04-02 9:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-03-31 8:30 about the speed Farkas Levente
2003-04-02 9:58 ` Illtud Daniel [this message]
2003-04-03 10:03 ` about the speed / XP RAID vs md Neil Brown
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