All of lore.kernel.org
 help / color / mirror / Atom feed
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 ;))


  reply	other threads:[~2008-05-29 11:22 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-05-28  8:53 Performance Characteristics of All Linux RAIDs (mdadm/bonnie++) Justin Piszcz
2008-05-28 10:54 ` Peter Rabbitson
2008-05-28 11:05   ` Justin Piszcz
2008-05-28 15:40 ` Chris Snook
2008-05-28 17:32   ` Justin Piszcz
2008-05-28 17:53     ` 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
2008-05-28 20:03   ` Richard Scobie
2008-05-28 20:01     ` Justin Piszcz
2008-05-28 16:34 ` Jens Bäckman
2008-05-28 16:40   ` Chris Snook
2008-05-28 16:40     ` Chris Snook
2008-05-28 16:46   ` Bryan Mesich
2008-05-28 16:46     ` Bryan Mesich
2008-05-28 17:33   ` Justin Piszcz
2008-05-28 18:57   ` Alan Cox
2008-05-28 18:57     ` Alan Cox
2008-05-28 23:00     ` Bill Davidsen
2008-05-28 23:00       ` Bill Davidsen
2008-05-29 11:22       ` Alan Cox [this message]
2008-05-30 12:22         ` Bill Davidsen
2008-05-28 19:02 ` Keld Jørn Simonsen
2008-05-28 19:05   ` Justin Piszcz
2008-05-28 23:09 ` Bill Davidsen
2008-05-29  6:37   ` Michal Soltys
2008-05-29  6:44 ` Holger Kiehl
2008-05-29 12:06   ` Justin Piszcz
2008-05-29 17:02   ` Justin Piszcz
2008-05-30 12:55     ` Bill Davidsen
2008-05-30 14:23       ` Keld Jørn Simonsen

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=20080529122223.462bf396@core \
    --to=alan@lxorguk.ukuu.org.uk \
    --cc=davidsen@tmr.com \
    --cc=jens.backman@gmail.com \
    --cc=jpiszcz@lucidpixels.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-raid@vger.kernel.org \
    --cc=xfs@oss.sgi.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.