From: Tommy Apel Hansen <tommyapeldk@gmail.com>
To: Charles Polisher <cpolish@surewest.net>
Cc: keld@keldix.com, Peter Rabbitson <rabbit+list@rabbit.us>,
Phil Turmel <philip@turmel.org>,
linux-raid@vger.kernel.org
Subject: Re: Suboptimal raid6 linear read speed
Date: Wed, 16 Jan 2013 07:37:33 +0100 [thread overview]
Message-ID: <1358318253.3022.3.camel@workstation-home> (raw)
In-Reply-To: <20130116044335.GA10165@kevin>
Hello,
1) you shouldn't use more than 2 drives for RAID1 as performance will be impacted (* at least that's what my own tests show)
2) for RAID10 use "2 far-copies" (-p f2) as that seems to be the most optimal layout
/Tommy
On Tue, 2013-01-15 at 20:43 -0800, Charles Polisher wrote:
> keld@keldix.com wrote:
> > > Advantage Advantage
> > > vs 4 drives vs RAID0
> > > Config Drives Seq write Seq read Write Read Write Read
> > > ------ ------ ---------- ---------- ----- ----- ---- ----
> > > RAID0 4 8.1MB/sec 9.3MB/sec 1.00 1.00 1.00 1.00
> > > RAID0 8 16.8MB/sec 15.0MB/sec 2.07 1.61 1.00 1.00
> > >
> > > RAID1 4 2.1MB/sec 3.6MB/sec 1.00 1.00 0.25 0.38
> > > RAID1 8 1.6MB/sec 3.6MB/sec 0.76 1.00 0.09 0.24
> > >
> > > RAID5 4 16.8MB/sec 9.1MB/sec 1.00 1.00 2.07 0.97
> > > RAID5 8 17.2MB/sec 14.9MB/sec 1.02 1.63 2.12 1.60
> > >
> > > RAID6 4 12.6MB/sec 7.9MB/sec 1.00 1.00 1.55 0.84
> > > RAID6 8 14.4MB/sec 14.5MB/sec 1.63 1.83 1.77 1.55
> > >
> > > RAID10 4 4.0MB/sec 7.3MB/sec 1.00 1.00 0.49 0.78
> > > RAID10 8 6.3MB/sec 13.4MB/sec 1.57 1.83 0.37 0.89
> > >
> > What layout are you using for RAID10?
> > Is it Linux MD RAID10?
>
> # cat /proc/mdstat
> Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath]
> md1 : active raid10 sdi[7] sdh[6] sdg[5] sdf[4] sde[3] sdd[2] sdc[1] sdb[0]
> 2118656 blocks 64K chunks 2 near-copies [8/8] [UUUUUUUU]
>
>
> --
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next prev parent reply other threads:[~2013-01-16 6:37 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-15 12:33 Suboptimal raid6 linear read speed Peter Rabbitson
2013-01-15 12:45 ` Mikael Abrahamsson
2013-01-15 12:56 ` Peter Rabbitson
2013-01-15 16:13 ` Mikael Abrahamsson
2013-01-15 12:49 ` Phil Turmel
2013-01-15 12:55 ` Peter Rabbitson
2013-01-15 17:09 ` Charles Polisher
2013-01-15 19:57 ` keld
2013-01-16 4:43 ` Charles Polisher
2013-01-16 6:37 ` Tommy Apel Hansen [this message]
2013-01-16 9:36 ` keld
2013-01-16 16:09 ` Charles Polisher
2013-01-16 20:40 ` EJ Vincent
2013-01-15 23:17 ` Phil Turmel
2013-01-16 2:48 ` Stan Hoeppner
2013-01-16 2:58 ` Peter Rabbitson
2013-01-16 20:29 ` Stan Hoeppner
2013-01-16 21:20 ` Roy Sigurd Karlsbakk
2013-01-17 15:51 ` Mikael Abrahamsson
2013-01-18 8:31 ` Stan Hoeppner
2013-01-18 9:18 ` Mikael Abrahamsson
2013-01-18 22:56 ` Stan Hoeppner
2013-01-19 7:43 ` Mikael Abrahamsson
2013-01-19 22:48 ` Stan Hoeppner
2013-01-19 23:51 ` Maarten
2013-01-20 0:16 ` Chris Murphy
2013-01-20 0:49 ` Maarten
2013-01-20 1:37 ` Phil Turmel
2013-01-20 9:44 ` Chris Murphy
2013-01-20 6:26 ` Mikael Abrahamsson
2013-01-20 9:39 ` Chris Murphy
2013-01-20 16:55 ` Mikael Abrahamsson
2013-01-20 17:15 ` Chris Murphy
2013-01-20 17:17 ` Mikael Abrahamsson
2013-01-20 17:20 ` Chris Murphy
2013-01-19 23:53 ` Phil Turmel
2013-01-20 9:04 ` Wolfgang Denk
2013-01-20 19:28 ` Peter Grandi
2013-01-20 21:09 ` Mikael Abrahamsson
2013-01-20 21:50 ` Peter Grandi
2013-01-21 5:24 ` Mikael Abrahamsson
2013-01-21 14:40 ` Peter Rabbitson
2013-01-21 20:32 ` Peter Grandi
2013-01-21 20:55 ` Peter Grandi
2013-01-21 22:00 ` Peter Grandi
2013-01-19 13:21 ` Roy Sigurd Karlsbakk
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