From: Michel <michel@ket.kth.se>
To: linux-raid@vger.kernel.org
Subject: Performance difference between two raid0 arrays on same drives?
Date: Fri, 11 Jul 2003 18:13:26 +0200 [thread overview]
Message-ID: <200307111813.26177.michel@ket.kth.se> (raw)
Hi!
I have set two raid0 arrays on two hardrives, using 2x2 partitions. I did a
benchmark of the resulting arrays and one is much slower than the other one.
I used bonnie++ and hdparm for the tests. It showed that /dev/md0 is 30%
slower than /dev/md1.
/dev/md1 is really close to twice the performance of a single drive.
I set the arrays with the same parameters. md0 is built from 2x 5 Gb while md1
is built from 2x2 Gb. The harddrives have the same partition table. md0 is
the closest to the begining of the drives.
The filessystem is Reiserfs on both arrays.
Everything works well, except i am curious about such a difference in
performances, since the arrays share the same hardware.
I am new to linux raid, i do not know if this is normal or weird.
Thanks for any help!
/etc/raidtab:
raiddev /dev/md0
raid-level 0
nr-raid-disks 2
persistent-superblock 1
chunk-size 32
device /dev/hde3
raid-disk 0
device /dev/hdg3
raid-disk 1
raiddev /dev/md1
raid-level 0
nr-raid-disks 2
persistent-superblock 1
chunk-size 32
device /dev/hde5
raid-disk 0
device /dev/hdg5
raid-disk 1
next reply other threads:[~2003-07-11 16:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-07-11 16:13 Michel [this message]
2003-07-12 4:36 ` Performance difference between two raid0 arrays on same drives? Gregory Leblanc
-- strict thread matches above, loose matches on Subject: below --
2003-07-12 13:37 Michel Bellais
2003-07-12 15:20 ` Gordon Henderson
2003-07-12 16:06 ` Michel Bellais
2003-07-12 15:49 ` Mads Peter Bach
2003-07-12 18:59 ` Michel Bellais
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=200307111813.26177.michel@ket.kth.se \
--to=michel@ket.kth.se \
--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).