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From: Stan Hoeppner <stan@hardwarefreak.com>
To: Richard Scobie <r.scobie@clear.net.nz>,
	Linux RAID Mailing List <linux-raid@vger.kernel.org>
Subject: Re: Triple parity and beyond
Date: Sun, 01 Dec 2013 22:30:57 -0600	[thread overview]
Message-ID: <529C0D01.4040903@hardwarefreak.com> (raw)
In-Reply-To: <529B77A1.3070602@clear.net.nz>

On 12/1/2013 11:53 AM, Richard Scobie wrote:
> Stan Hoeppner wrote:
> 
>> ZERO SATA drives are dual ported.  The vast majority of people using
>> md/RAID are using SATA disks, not SAS.
> 
> While admittedly uncommon, they are available.
> 
> http://h30094.www3.hp.com/product/sku/10435415

Assuming that's not a misprint, then this is not a dual ported SATA
drive.  The SATA protocol doesn't support this.  This is a SATA drive in
HP's vendor proprietary carrier with a proprietary factory integrated
external SAS interposer card hanging off the back.  This interposer
allows you to add this SATA drive to an HP dual ported SAS enclosure
backplane and HBAs.  They also offer an interposer to drop SATA drives
into FC enclosures.

Note these SAS-SATA interposers require SAS HBAs and an SAS enclosure.
Given the small price difference between SATA drives w/interposer, and
native nearline SAS drives, and the greater reliability/warranty of the
latter, I don't think you'll see many folks buying these interposer
drives.  Especially given the required investment in SAS infrastructure
between the drives and host.

See:

http://serialstoragewire.net/Articles/2007_07/developer24.html
http://en.wikipedia.org/wiki/Interposer

-- 
Stan

  reply	other threads:[~2013-12-02  4:30 UTC|newest]

Thread overview: 104+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-01 17:53 Triple parity and beyond Richard Scobie
2013-12-02  4:30 ` Stan Hoeppner [this message]
  -- strict thread matches above, loose matches on Subject: below --
2013-11-18 22:08 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
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

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