From: Stan Hoeppner <stan@hardwarefreak.com>
To: John Williams <jwilliams4200@gmail.com>
Cc: James Plank <plank@cs.utk.edu>, Ric Wheeler <rwheeler@redhat.com>,
Andrea Mazzoleni <amadvance@gmail.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Linux RAID Mailing List <linux-raid@vger.kernel.org>,
Btrfs BTRFS <linux-btrfs@vger.kernel.org>,
David Brown <david.brown@hesbynett.no>,
David Smith <creamyfish@gmail.com>
Subject: Re: Triple parity and beyond
Date: Thu, 21 Nov 2013 00:52:33 -0600 [thread overview]
Message-ID: <528DADB1.8010604@hardwarefreak.com> (raw)
In-Reply-To: <CAJBj3vf7Ot2oUkk6LtkWRouFqrSCKecz0yD4Ds5UGT1BL1ds5A@mail.gmail.com>
On 11/20/2013 8:46 PM, John Williams wrote:
> For myself or any machines I managed for work that do not need high
> IOPS, I would definitely choose triple- or quad-parity over RAID 51 or
> similar schemes with arrays of 16 - 32 drives.
You must see a week long rebuild as acceptable...
> No need to go into detail here
I disagree.
> on a subject Adam Leventhal has already
> covered in detail in an article "Triple-Parity RAID and Beyond" which
> seems to match the subject of this thread quite nicely:
>
> http://queue.acm.org/detail.cfm?id=1670144
Mr. Leventhal did not address the overwhelming problem we face, which is
(multiple) parity array reconstruction time. He assumes the time to
simply 'populate' one drive at its max throughput is the total
reconstruction time for the array. While this is typically true for
mirror based arrays, it is clearly not for parity arrays.
The primary focus of my comments was reducing rebuild time, thus
increasing overall reliability. RAID 51 or something similar would
achieve this. Thus I think we should discuss alternatives to multiple
parity in detail.
--
Stan
next prev parent reply other threads:[~2013-11-21 6:52 UTC|newest]
Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-18 22:08 Triple parity and beyond Andrea Mazzoleni
2013-11-18 22:12 ` H. Peter Anvin
2013-11-18 22:35 ` Andrea Mazzoleni
2013-11-18 23:25 ` H. Peter Anvin
2013-11-19 10:16 ` David Brown
2013-11-19 17:36 ` Andrea Mazzoleni
2013-11-19 22:51 ` Drew
2013-11-20 0:54 ` Chris Murphy
2013-11-20 1:23 ` John Williams
2013-11-20 10:35 ` David Brown
2013-11-20 10:31 ` David Brown
2013-11-20 18:09 ` John Williams
2013-11-20 18:44 ` Andrea Mazzoleni
2013-11-21 6:15 ` Stan Hoeppner
2013-11-21 8:32 ` David Brown
2013-11-20 18:34 ` Andrea Mazzoleni
2013-11-20 18:43 ` H. Peter Anvin
2013-11-20 18:56 ` Andrea Mazzoleni
2013-11-20 18:59 ` H. Peter Anvin
2013-11-20 21:21 ` Andrea Mazzoleni
2013-11-20 19:00 ` H. Peter Anvin
2013-11-20 21:04 ` Andrea Mazzoleni
2013-11-20 21:06 ` H. Peter Anvin
2013-11-21 8:36 ` David Brown
2013-11-19 17:28 ` Andrea Mazzoleni
2013-11-19 20:29 ` Ric Wheeler
2013-11-20 16:16 ` James Plank
2013-11-20 19:05 ` Andrea Mazzoleni
2013-11-20 19:10 ` H. Peter Anvin
2013-11-20 20:30 ` James Plank
2013-11-20 21:23 ` Andrea Mazzoleni
2013-11-27 2:50 ` ronnie sahlberg
2013-11-20 21:28 ` H. Peter Anvin
2013-11-21 1:28 ` Stan Hoeppner
2013-11-21 2:46 ` John Williams
2013-11-21 6:52 ` Stan Hoeppner [this message]
2013-11-21 7:05 ` John Williams
2013-11-21 22:57 ` Stan Hoeppner
2013-11-21 23:38 ` John Williams
2013-11-22 9:35 ` Stan Hoeppner
2013-11-22 11:24 ` joystick
2013-11-22 15:01 ` John Williams
2013-11-22 22:28 ` Stan Hoeppner
2013-11-22 23:07 ` NeilBrown
2013-11-23 3:46 ` Stan Hoeppner
2013-11-23 5:04 ` NeilBrown
2013-11-23 5:34 ` John Williams
2013-11-23 7:12 ` NeilBrown
2013-11-24 4:03 ` Stan Hoeppner
2013-11-24 5:14 ` John Williams
2013-11-24 21:13 ` Stan Hoeppner
2013-11-24 23:28 ` Rudy Zijlstra
2013-11-24 23:53 ` Alex Elsayed
2013-11-25 2:04 ` Stan Hoeppner
2013-11-25 4:48 ` Alex Elsayed
2013-11-25 9:15 ` David Brown
2013-11-24 5:19 ` Russell Coker
2013-11-24 21:44 ` Stan Hoeppner
2013-11-24 22:31 ` Mark Knecht
2013-11-25 2:14 ` Russell Coker
2013-11-25 9:20 ` David Brown
2013-11-21 8:08 ` joystick
2013-11-22 0:30 ` Stan Hoeppner
2013-11-22 0:33 ` H. Peter Anvin
2013-11-22 0:45 ` David Brown
2013-11-21 9:07 ` David Brown
2013-11-21 9:54 ` Adam Goryachev
2013-11-21 10:32 ` David Brown
2013-11-22 8:12 ` Russell Coker
2013-11-25 18:23 ` Pasi Kärkkäinen
2013-11-22 8:13 ` Stan Hoeppner
2013-11-22 13:15 ` David Brown
2013-11-22 16:07 ` Stan Hoeppner
2013-11-22 22:59 ` NeilBrown
2013-11-23 17:39 ` David Brown
2013-11-22 16:50 ` Mark Knecht
2013-11-22 19:51 ` Duncan
2013-11-22 8:38 ` Stan Hoeppner
2013-11-22 13:24 ` David Brown
2013-11-28 7:16 ` Stan Hoeppner
2013-11-28 7:36 ` Russell Coker
2013-11-28 9:56 ` David Brown
2013-11-30 7:32 ` Alex Elsayed
2013-12-01 15:37 ` Stan Hoeppner
2013-11-22 14:19 ` David Taylor
2013-11-21 19:56 ` Piergiorgio Sartor
2013-11-19 18:12 ` Piergiorgio Sartor
2013-11-20 10:44 ` David Brown
2013-11-20 21:59 ` Piergiorgio Sartor
2013-11-21 10:13 ` David Brown
2013-11-21 17:37 ` Goffredo Baroncelli
2013-11-21 20:05 ` Piergiorgio Sartor
2013-11-21 20:31 ` David Brown
2013-11-21 20:52 ` Piergiorgio Sartor
2013-11-22 0:32 ` David Brown
2013-11-22 20:32 ` Piergiorgio Sartor
2013-11-26 18:10 ` joystick
2013-11-20 21:38 ` Andrea Mazzoleni
2013-11-20 22:29 ` Piergiorgio Sartor
2013-11-23 7:55 ` Andrea Mazzoleni
2013-11-23 22:10 ` Piergiorgio Sartor
2013-11-24 9:39 ` Andrea Mazzoleni
-- strict thread matches above, loose matches on Subject: below --
2013-12-01 17:53 Richard Scobie
2013-12-02 4:30 ` Stan Hoeppner
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