From: Stan Hoeppner <stan@hardwarefreak.com>
To: Adam Goryachev <mailinglists@websitemanagers.com.au>
Cc: Phil Turmel <philip@turmel.org>, Linux RAID <linux-raid@vger.kernel.org>
Subject: Re: RAID performance - new kernel results - 5x SSD RAID5
Date: Sun, 03 Mar 2013 23:25:21 -0600 [thread overview]
Message-ID: <51343041.9010305@hardwarefreak.com> (raw)
In-Reply-To: <ac5cdf66-ba01-4d7b-bd7b-60fb67517ad4@email.android.com>
On 3/3/2013 9:19 AM, Adam Goryachev wrote:
> Phil Turmel <philip@turmel.org> wrote:
...
>> Run "dmsetup table" and look at the start sectors for your volumes:
>> Fast-Root: 0 314572800 linear 9:3 3072
>> This volume starts at sector 3072 (1.5MB) on /dev/sda3. So the volume
>> alignment within LVM is 512K.
>
> I see this (for the first LV)
> vg0-hostname: 0 204808192 linear 147:2 512
> So, I'm guessing mine is starting at 512, and is also aligned at 512k ?
>
> Also, pvdisplay tells me the PE Size is 4M, so I'm assuming that regardless of how the LV's are arranged, they will always be 512k aligned?
>
> So, is that enough to be sure that this is not an issue?
If it starts at sector 512, that should be the first sector of the 2nd
md/RAID stripe, so the first sector of the LV is aligned. 204,808,192
sectors divided by a 256KB stripe width equals 400,016 stripes (a whole
number), so this partition is correctly aligned to the RAID device. If
you have no gaps between this one and your other LVs, and each of them
is evenly divisible by 512 sectors, then they should all be aligned.
--
Stan
next prev parent reply other threads:[~2013-03-04 5:25 UTC|newest]
Thread overview: 131+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-07 6:48 RAID performance Adam Goryachev
2013-02-07 6:51 ` Adam Goryachev
2013-02-07 8:24 ` Stan Hoeppner
2013-02-07 7:02 ` Carsten Aulbert
2013-02-07 10:12 ` Adam Goryachev
2013-02-07 10:29 ` Carsten Aulbert
2013-02-07 10:41 ` Adam Goryachev
2013-02-07 8:11 ` Stan Hoeppner
2013-02-07 10:05 ` Adam Goryachev
2013-02-16 4:33 ` RAID performance - *Slow SSDs likely solved* Stan Hoeppner
[not found] ` <cfefe7a6-a13f-413c-9e3d-e061c68dc01b@email.android.com>
2013-02-17 5:01 ` Stan Hoeppner
2013-02-08 7:21 ` RAID performance Adam Goryachev
2013-02-08 7:37 ` Chris Murphy
2013-02-08 13:04 ` Stan Hoeppner
2013-02-07 9:07 ` Dave Cundiff
2013-02-07 10:19 ` Adam Goryachev
2013-02-07 11:07 ` Dave Cundiff
2013-02-07 12:49 ` Adam Goryachev
2013-02-07 12:53 ` Phil Turmel
2013-02-07 12:58 ` Adam Goryachev
2013-02-07 13:03 ` Phil Turmel
2013-02-07 13:08 ` Adam Goryachev
2013-02-07 13:20 ` Mikael Abrahamsson
2013-02-07 22:03 ` Chris Murphy
2013-02-07 23:48 ` Chris Murphy
2013-02-08 0:02 ` Chris Murphy
2013-02-08 6:25 ` Adam Goryachev
2013-02-08 7:35 ` Chris Murphy
2013-02-08 8:34 ` Chris Murphy
2013-02-08 14:31 ` Adam Goryachev
2013-02-08 14:19 ` Adam Goryachev
2013-02-08 6:15 ` Adam Goryachev
2013-02-07 15:32 ` Dave Cundiff
2013-02-08 13:58 ` Adam Goryachev
2013-02-08 21:42 ` Stan Hoeppner
2013-02-14 22:42 ` Chris Murphy
2013-02-15 1:10 ` Adam Goryachev
2013-02-15 1:40 ` Chris Murphy
2013-02-15 4:01 ` Adam Goryachev
2013-02-15 5:14 ` Chris Murphy
2013-02-15 11:10 ` Adam Goryachev
2013-02-15 23:01 ` Chris Murphy
2013-02-17 9:52 ` RAID performance - new kernel results Adam Goryachev
2013-02-18 13:20 ` RAID performance - new kernel results - 5x SSD RAID5 Stan Hoeppner
2013-02-20 17:10 ` Adam Goryachev
2013-02-21 6:04 ` Stan Hoeppner
2013-02-21 6:40 ` Adam Goryachev
2013-02-21 8:47 ` Joseph Glanville
2013-02-22 8:10 ` Stan Hoeppner
2013-02-24 20:36 ` Stan Hoeppner
2013-03-01 16:06 ` Adam Goryachev
2013-03-02 9:15 ` Stan Hoeppner
2013-03-02 17:07 ` Phil Turmel
2013-03-02 23:48 ` Stan Hoeppner
2013-03-03 2:35 ` Phil Turmel
2013-03-03 15:19 ` Adam Goryachev
2013-03-04 1:31 ` Phil Turmel
2013-03-04 9:39 ` Adam Goryachev
2013-03-04 12:41 ` Phil Turmel
2013-03-04 12:42 ` Stan Hoeppner
2013-03-04 5:25 ` Stan Hoeppner [this message]
2013-03-03 17:32 ` Adam Goryachev
2013-03-04 12:20 ` Stan Hoeppner
2013-03-04 16:26 ` Adam Goryachev
2013-03-05 9:30 ` RAID performance - 5x SSD RAID5 - effects of stripe cache sizing Stan Hoeppner
2013-03-05 15:53 ` Adam Goryachev
2013-03-07 7:36 ` Stan Hoeppner
2013-03-08 0:17 ` Adam Goryachev
2013-03-08 4:02 ` Stan Hoeppner
2013-03-08 5:57 ` Mikael Abrahamsson
2013-03-08 10:09 ` Stan Hoeppner
2013-03-08 14:11 ` Mikael Abrahamsson
2013-02-21 17:41 ` RAID performance - new kernel results - 5x SSD RAID5 David Brown
2013-02-23 6:41 ` Stan Hoeppner
2013-02-23 15:57 ` RAID performance - new kernel results John Stoffel
2013-03-01 16:10 ` Adam Goryachev
2013-03-10 15:35 ` Charles Polisher
2013-04-15 12:23 ` Adam Goryachev
2013-04-15 15:31 ` John Stoffel
2013-04-17 10:15 ` Adam Goryachev
2013-04-15 16:49 ` Roy Sigurd Karlsbakk
2013-04-15 20:16 ` Phil Turmel
2013-04-16 19:28 ` Roy Sigurd Karlsbakk
2013-04-16 21:03 ` Phil Turmel
2013-04-16 21:43 ` Stan Hoeppner
2013-04-15 20:42 ` Stan Hoeppner
2013-02-08 3:32 ` RAID performance Stan Hoeppner
2013-02-08 7:11 ` Adam Goryachev
2013-02-08 17:10 ` Stan Hoeppner
2013-02-08 18:44 ` Adam Goryachev
2013-02-09 4:09 ` Stan Hoeppner
2013-02-10 4:40 ` Adam Goryachev
2013-02-10 13:22 ` Stan Hoeppner
2013-02-10 16:16 ` Adam Goryachev
2013-02-10 17:19 ` Mikael Abrahamsson
2013-02-10 21:57 ` Adam Goryachev
2013-02-11 3:41 ` Adam Goryachev
2013-02-11 4:33 ` Mikael Abrahamsson
2013-02-12 2:46 ` Stan Hoeppner
2013-02-12 5:33 ` Adam Goryachev
2013-02-13 7:56 ` Stan Hoeppner
2013-02-13 13:48 ` Phil Turmel
2013-02-13 16:17 ` Adam Goryachev
2013-02-13 20:20 ` Adam Goryachev
2013-02-14 12:22 ` Stan Hoeppner
2013-02-15 13:31 ` Stan Hoeppner
2013-02-15 14:32 ` Adam Goryachev
2013-02-16 1:07 ` Stan Hoeppner
2013-02-16 17:19 ` Adam Goryachev
2013-02-17 1:42 ` Stan Hoeppner
2013-02-17 5:02 ` Adam Goryachev
2013-02-17 6:28 ` Stan Hoeppner
2013-02-17 8:41 ` Adam Goryachev
2013-02-17 13:58 ` Stan Hoeppner
2013-02-17 14:46 ` Adam Goryachev
2013-02-19 8:17 ` Stan Hoeppner
2013-02-20 16:45 ` Adam Goryachev
2013-02-21 0:45 ` Stan Hoeppner
2013-02-21 3:10 ` Adam Goryachev
2013-02-22 11:19 ` Stan Hoeppner
2013-02-22 15:25 ` Charles Polisher
2013-02-23 4:14 ` Stan Hoeppner
2013-02-12 7:34 ` Mikael Abrahamsson
2013-02-08 7:17 ` Adam Goryachev
2013-02-07 12:01 ` Brad Campbell
2013-02-07 12:37 ` Adam Goryachev
2013-02-07 17:12 ` Fredrik Lindgren
2013-02-08 0:00 ` Adam Goryachev
2013-02-11 19:49 ` Roy Sigurd Karlsbakk
2013-02-11 20:30 ` Dave Cundiff
2013-02-07 11:32 ` Mikael Abrahamsson
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