From: Stan Hoeppner <stan@hardwarefreak.com>
To: Roman Mamedov <rm@romanrm.ru>
Cc: NeilBrown <neilb@suse.de>,
Kasper Sandberg <kontakt@sandberg-consult.dk>,
linux-raid@vger.kernel.org
Subject: Re: raid6 low performance 8x3tb drives in singledegraded mode(=7x3tb)
Date: Wed, 19 Sep 2012 11:31:33 -0500 [thread overview]
Message-ID: <5059F365.8000400@hardwarefreak.com> (raw)
In-Reply-To: <20120919134030.222e4b04@natsu>
On 9/19/2012 2:40 AM, Roman Mamedov wrote:
> "/sys/block/md*/md/stripe_cache_size" is absolutely the first thing one should
> look at when facing a problem with md RAID5/6 write performance.
No. The first thing one should do is verify that the md/RAID stripe is
properly aligned to physical sector boundaries on the drives, and that
the filesystem is properly aligned to the md/RAID stripe size. If these
are not correct then tweaking stripe_cache_size isn't going to help
much, if at all.
--
Stan
next prev parent reply other threads:[~2012-09-19 16:31 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-12 0:03 raid6 low performance 8x3tb drives in singledegraded mode(=7x3tb) Kasper Sandberg
2012-09-12 9:42 ` Peter Grandi
2012-09-12 13:38 ` Peter Grandi
2012-09-19 6:25 ` NeilBrown
2012-09-19 7:40 ` Roman Mamedov
2012-09-19 16:31 ` Stan Hoeppner [this message]
2012-09-20 0:26 ` Kasper Sandberg
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