From: Roman Mamedov <rm@romanrm.net>
To: Ming Lin <mlin@kernel.org>
Cc: linux-raid@vger.kernel.org, Neil Brown <neilb@suse.de>
Subject: Re: write performance of HW RAID VS MD RAID
Date: Thu, 11 Jun 2015 05:27:29 +0500 [thread overview]
Message-ID: <20150611052729.258dddfa@natsu> (raw)
In-Reply-To: <CAF1ivSa644NVVd5R=2g8rvbZ-FK5cgXy_U1XJjYwMf+TJdftCw@mail.gmail.com>
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On Wed, 10 Jun 2015 15:27:07 -0700
Ming Lin <mlin@kernel.org> wrote:
> Hi NeilBrown,
>
> As you may already see, I run a lot of tests with 10 HDDs for the patchset
> "simplify block layer based on immutable biovecs"
>
> Here is the summary.
> http://minggr.net/pub/20150608/fio_results/summary.log
>
> MD RAID6 read performance is OK.
> But write performance is much lower than HW RAID6.
>
> Is it a known issue?
Did you tune the stripe_cache_size for the array? Try 32768.
https://peterkieser.com/2009/11/29/raid-mdraid-stripe_cache_size-vs-write-transfer/
--
With respect,
Roman
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next prev parent reply other threads:[~2015-06-11 0:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-10 22:27 write performance of HW RAID VS MD RAID Ming Lin
2015-06-10 23:00 ` Neil Brown
2015-06-10 23:34 ` Steven Haigh
2015-06-10 23:59 ` Ming Lin
2015-06-11 0:28 ` Neil Brown
2015-06-11 0:27 ` Roman Mamedov [this message]
2015-06-11 5:39 ` AW: " Markus Stockhausen
2015-06-11 6:02 ` Ming Lin
2015-06-12 17:20 ` Ming Lin
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