From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Bill Davidsen <davidsen@tmr.com>
Cc: "Jens Bäckman" <jens.backman@gmail.com>,
"Justin Piszcz" <jpiszcz@lucidpixels.com>,
linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
xfs@oss.sgi.com
Subject: Re: Performance Characteristics of All Linux RAIDs (mdadm/bonnie++)
Date: Thu, 29 May 2008 12:22:23 +0100 [thread overview]
Message-ID: <20080529122223.462bf396@core> (raw)
In-Reply-To: <483DE40D.8090608@tmr.com>
> I really don't think that's any part of the issue, the same memory and
> bridge went 4-5x faster in other read cases. The truth is that the
> raid-1 performance is really bad, and it's the code causing it AFAIK. If
> you track the actual io it seems to read one drive at a time, in order,
> without overlap.
Make sure the readahead is set to be a fair bit over the stripe size if
you are doing bulk data tests for a single file. (Or indeed in the real
world for that specific case ;))
next prev parent reply other threads:[~2008-05-29 11:35 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <alpine.DEB.1.10.0805280442330.4527@p34.internal.lan>
[not found] ` <483D39D3.4020906@rabbit.us>
2008-05-28 11:05 ` Performance Characteristics of All Linux RAIDs (mdadm/bonnie++) Justin Piszcz
2008-05-28 15:40 ` Chris Snook
2008-05-28 17:32 ` Justin Piszcz
2008-05-28 19:22 ` Chris Snook
2008-05-28 19:27 ` Justin Piszcz
2008-05-29 9:57 ` Kasper Sandberg
2008-05-29 21:08 ` Justin Piszcz
[not found] ` <95711f160805280934y77ed7d91tec5aeb531bf8013c@mail.gmail.com>
2008-05-28 16:40 ` Chris Snook
2008-05-28 16:46 ` Bryan Mesich
[not found] ` <20080528195752.0cdcbc6d@core>
[not found] ` <483DE40D.8090608@tmr.com>
2008-05-29 11:22 ` Alan Cox [this message]
2008-05-30 12:22 ` Bill Davidsen
[not found] ` <20080528190242.GA5171@rap.rap.dk>
2008-05-28 19:05 ` Justin Piszcz
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