From: "Keld Jørn Simonsen" <keld@dkuug.dk>
To: linux-raid@vger.kernel.org
Subject: Re: performance problems with raid10,f2
Date: Thu, 20 Mar 2008 18:28:17 +0100 [thread overview]
Message-ID: <20080320172817.GA27070@rap.rap.dk> (raw)
In-Reply-To: <20080314231151.GA14568@rap.rap.dk>
On Sat, Mar 15, 2008 at 12:11:51AM +0100, Keld Jørn Simonsen wrote:
> Hi
>
> I have a 4 drive array with 1 TB Hitachi disks, formatted as raid10,f2
>
> I had some strange observations:
>
> 1. while resyncing I could get the raid to give me about 320 MB/s in
> sequential read, which was good. After resync had been done, and with
> all 4 drives active, I only get 115 MB/s.
This was reproducable. I dont know what could be wrong.
I tried to enlarge my readahed, but the system did not allow me to have
more than a 2 MiB readahed, - well that should be ok for a 4 disk array
with 256 kiB chunks?
I did try to have chunks of 64 kiB - but no luck.
It seemed like it is something that the resync process builds up.
What could it be?
Best regards
keld
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next prev parent reply other threads:[~2008-03-20 17:28 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-14 23:11 performance problems with raid10,f2 Keld Jørn Simonsen
2008-03-20 17:28 ` Keld Jørn Simonsen [this message]
2008-03-25 5:13 ` Neil Brown
2008-03-25 10:36 ` Keld Jørn Simonsen
2008-03-25 13:22 ` Peter Grandi
2008-04-02 21:13 ` Keld Jørn Simonsen
2008-04-03 20:20 ` Peter Grandi
2008-04-04 8:03 ` Keld Jørn Simonsen
2008-04-05 17:31 ` Peter Grandi
2008-04-05 18:46 ` Keld Jørn Simonsen
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