From: Raz <raziebe@gmail.com>
To: Jon Nelson <jnelson-linux-raid@jamponi.net>
Cc: Linux RAID Mailing List <linux-raid@vger.kernel.org>
Subject: Re: stripe_cache_size and performance
Date: Thu, 21 Jun 2007 21:42:56 +0200 [thread overview]
Message-ID: <5d96567b0706211242p7f03bd1cw9102ae3e44d67cee@mail.gmail.com> (raw)
In-Reply-To: <Pine.LNX.4.64.0706211312480.5806@gheavc.wnzcbav.cig>
What is your raid configuration ?
Please note that the stripe_cache_size is acting as a bottle neck in some cases.
On 6/21/07, Jon Nelson <jnelson-linux-raid@jamponi.net> wrote:
>
> I've been futzing with stripe_cache_size on a 3x component raid5,
> using 2.6.18.8-0.3-default on x86_64 (openSUSE 10.2).
>
> With the value set at 4096 I get pretty great write numbers.
> 2048 and on down the write numbers slowly drop.
>
> However, at values above 512 the 'check' performance is terrible. By
> 'check' performance I mean the value displayed by /proc/mdstat after
> I issue:
>
> echo check > /sys/block/md0/md/sync_action
>
> When I say "terrible" I mean < 3MB/s.
> When I use 384, the performance goes to ~70MB/s
> 512.. 72-73MB/s
> 640.. 73-74MB/s
>
> 768.. 3300 K/s. Wow!
>
> Can somebody 'splain to me what is going on?
>
> --
> Jon Nelson <jnelson-linux-raid@jamponi.net>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
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>
--
Raz
next prev parent reply other threads:[~2007-06-21 19:42 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-21 18:28 stripe_cache_size and performance Jon Nelson
2007-06-21 19:42 ` Raz [this message]
2007-06-21 23:09 ` Jon Nelson
2007-06-22 15:01 ` Raz
2007-06-22 15:10 ` Justin Piszcz
2007-06-25 16:48 ` Bill Davidsen
2007-06-25 17:00 ` Justin Piszcz
2007-06-25 18:20 ` Justin Piszcz
2007-06-25 18:21 ` Justin Piszcz
2007-06-25 18:42 ` Justin Piszcz
2007-06-25 19:48 ` stripe_cache_size and performance [BUG with =64kb] Justin Piszcz
2007-06-25 19:49 ` Justin Piszcz
2007-06-25 20:36 ` Justin Piszcz
2007-06-25 20:42 ` Justin Piszcz
2007-06-25 22:12 ` stripe_cache_size and performance Jon Nelson
2007-06-25 22:19 ` Dan Williams
2007-06-25 23:23 ` Jon Nelson
2007-06-25 22:21 ` Justin Piszcz
2007-06-26 13:58 ` Jon Nelson
2007-06-26 14:00 ` Justin Piszcz
2007-06-26 14:16 ` Jon Nelson
2007-06-26 14:37 ` Justin Piszcz
2007-06-26 15:22 ` Jon Nelson
2007-06-26 15:54 ` Justin Piszcz
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