From: Neil Brown <neilb@suse.de>
To: sminded <daniel.zetterman@gmail.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: Faster read performance DURING (?) resync on raid10
Date: Fri, 26 Sep 2008 14:18:19 +1000 [thread overview]
Message-ID: <18652.25227.7530.435789@notabene.brown> (raw)
In-Reply-To: message from sminded on Thursday September 25
On Thursday September 25, daniel.zetterman@gmail.com wrote:
>
> I have done some automated scripted tests with bonnie++ over RAID10 and
> encryption, using different encryption cipher modes to evaluate the impact
> on I/O operations.
> The strange thing is that I can see a significant increase in read
> performance (about 20%) when running the tests DURING the raid resync phase
> directly after the raid creation as appose to running it after the resync,
> or after I create the array with --assume-clean (which skips initial
> resync).
Sounds like the read-balancing is doing exactly the wrong thing -
quite possible.
What layout are you using (near, far, offset?), how many devices?
NeilBrown
next prev parent reply other threads:[~2008-09-26 4:18 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-25 9:27 Faster read performance DURING (?) resync on raid10 sminded
2008-09-25 18:40 ` Keld J�rn Simonsen
2008-09-26 4:18 ` Neil Brown [this message]
2008-09-26 23:19 ` Daniel Zetterman
2008-09-28 2:23 ` Keld J�rn Simonsen
2008-09-28 10:45 ` Daniel Zetterman
2008-09-28 11:06 ` Daniel Zetterman
2008-09-28 17:35 ` Keld Jørn Simonsen
2008-09-26 8:03 ` John Robinson
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