linux-raid.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Keld Jørn Simonsen" <keld@dkuug.dk>
To: linux-raid@vger.kernel.org
Subject: performance of raid10,f2 on 4 disks
Date: Wed, 23 Jan 2008 19:21:20 +0100	[thread overview]
Message-ID: <20080123182120.GA26044@rap.rap.dk> (raw)

Hi!

I have played around with raid10,f2 on a 2 disk array set,
and I really liked the performance on the sequential reads.
It looked like double up on the speed, about 173 MB/s
for two SATA-2 disks. 

I then went on to look at my 4 new SATS-2 disks, to have
the same kind of performance I made the array by:

mdadm --create /dev/md3 --chunk=256 -R -l 10 -n 4 -p f2 /dev/sd[abcd]1

And my first tests showed a sequential read rate of 320 MB/s.
Impressive! I then tried it a few more times, but then I could not
get more than around 160 MB/s, which is less than what I got on 2 disks.

Any ideas of what is going on?

Best regards
keld

                 reply	other threads:[~2008-01-23 18:21 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=20080123182120.GA26044@rap.rap.dk \
    --to=keld@dkuug.dk \
    --cc=linux-raid@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;
as well as URLs for NNTP newsgroup(s).