From: NeilBrown <neilb@suse.de>
To: Liam Kurmos <quantum.leaf@gmail.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: mdadm raid1 read performance
Date: Wed, 4 May 2011 10:58:22 +1000 [thread overview]
Message-ID: <20110504105822.21e23bc3@notabene.brown> (raw)
In-Reply-To: <BANLkTim8Ehn0fANtibg7X1cMVvOgt7CNMA@mail.gmail.com>
On Wed, 4 May 2011 01:07:45 +0100 Liam Kurmos <quantum.leaf@gmail.com> wrote:
> Hi,
>
> I've been testing mdadm (great piece of software btw) however all my
> test show that reading from raid1 is only the same speed as reading
> from a single drive.
Why do you expect RAID1 to be faster? On a single threaded sequential read
there is not much it can do to go faster than a single device. Maybe on some
multi-thread random IOs it might.
What sort of tests were you running?
NeilBrown
>
> Is this a known issue? or is there something seriously wrong with my
> system? i have tried v2.8.1 and v.3.2.1 without difference and several
> benchmarking methods.
>
> best regards,
>
> Liam
next prev parent reply other threads:[~2011-05-04 0:58 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-04 0:07 mdadm raid1 read performance Liam Kurmos
2011-05-04 0:57 ` John Robinson
2011-05-06 20:44 ` Leslie Rhorer
2011-05-06 21:56 ` Keld Jørn Simonsen
2011-05-04 0:58 ` NeilBrown [this message]
2011-05-04 5:30 ` Drew
2011-05-04 6:31 ` Brad Campbell
2011-05-04 7:42 ` Roberto Spadim
2011-05-04 23:08 ` Liam Kurmos
2011-05-04 23:35 ` Roberto Spadim
2011-05-04 23:36 ` Brad Campbell
2011-05-04 23:45 ` NeilBrown
2011-05-04 23:57 ` Roberto Spadim
2011-05-05 0:14 ` Liam Kurmos
2011-05-05 0:20 ` Liam Kurmos
2011-05-05 0:25 ` Roberto Spadim
2011-05-05 0:40 ` Liam Kurmos
2011-05-05 7:26 ` David Brown
2011-05-05 10:41 ` Keld Jørn Simonsen
2011-05-05 11:38 ` David Brown
2011-05-06 4:14 ` CoolCold
2011-05-06 7:29 ` David Brown
2011-05-06 21:05 ` Leslie Rhorer
2011-05-07 10:37 ` David Brown
2011-05-07 10:58 ` Keld Jørn Simonsen
2011-05-05 0:24 ` Roberto Spadim
2011-05-05 11:10 ` Keld Jørn Simonsen
2011-05-06 21:20 ` Leslie Rhorer
2011-05-06 21:53 ` Keld Jørn Simonsen
2011-05-07 3:17 ` Leslie Rhorer
2011-05-05 4:06 ` Roman Mamedov
2011-05-05 8:06 ` Nikolay Kichukov
2011-05-05 8:39 ` Liam Kurmos
2011-05-05 8:49 ` Liam Kurmos
2011-05-05 9:30 ` NeilBrown
2011-05-04 7:48 ` David Brown
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