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From: "Keld Jørn Simonsen" <keld@keldix.com>
To: Stan Hoeppner <stan@hardwarefreak.com>
Cc: "Keld Jørn Simonsen" <keld@keldix.com>,
	"Jon Nelson" <jnelson-linux-raid@jamponi.net>,
	"Mathias Burén" <mathias.buren@gmail.com>,
	"Roberto Spadim" <roberto@spadim.com.br>,
	Denis <denismpa@gmail.com>,
	Linux-RAID <linux-raid@vger.kernel.org>
Subject: Re: What's the typical RAID10 setup?
Date: Fri, 4 Feb 2011 10:06:03 +0100	[thread overview]
Message-ID: <20110204090602.GA4017@www2.open-std.org> (raw)
In-Reply-To: <4D4BB87A.30800@hardwarefreak.com>

On Fri, Feb 04, 2011 at 02:27:38AM -0600, Stan Hoeppner wrote:
> Keld Jørn Simonsen put forth on 2/4/2011 1:06 AM:
> 
> > Well RAID1+0 is not the best combination available. I would argue that
> > raid10,f2 is significantly better in a number of areas.
> 
> I'd guess Linux software RAID would be lucky to have 1% of RAID deployments
> worldwide--very lucky.  The other 99%+ are HBA RAID or SAN/NAS "appliances" most
> often using custom embedded RTOS with the RAID code written in assembler,
> especially in the case of the HBAs.  For everything not Linux mdraid, RAID 10
> (aka 1+0) is king of the hill, and has been for 15 years+

Yes, you are right, Linux MD really has an advantage here:-)

> >> Something smells bad here.  Does one of the RAID companies own a patent or
> >> trademark on "RAID 10"?  I'll look into this.  It just doesn't make any sense
> >> for RAID 10 to be omitted from the SNIA DDF but to be referenced in the manner
> >> it is.
> > 
> > It looks like they do define all major basic RAID disk layouts. (except
> > raid10,f2 of cause) . RAID1+0 is a derived format, maybe that is out of
> > scope of the DDF standard.
> 
> "A secondary virtual disk is a VD configured using hybrid RAID levels like
> RAID10 or RAID50. Its elements are BVDs."
> 
> So apparently their Disk Data Format specification doesn't include hybrid RAID
> levels.  This makes sense, as the _on disk_ layout of RAID 10 is identical to
> RAID 1.

Yes, raid10 is just a variation of RAID1, actually raid10,n2 is
identical on the disk to RAID1, eg for a 2 drive or 4-drive array.

> We apparently need to be looking for other SNIA documents to find their
> definition of RAID 10.  That is what started us down this tunnel isn't it?
> We're so deep now there's no light and I can't see the path behind me anymore. ;)

I dont think SNIA defines RAID 10, which is a specific Linux MD thing.

For RAID1+0, I think it is covered by the DDF standard, as what DDF is
aimed at is defining formats on the disks to portably handle RAID. That
means that you can move a set of disks used in one manufacturer's 
configuration  to another make's  configuration, and it will still work.

And it will also work with RAID1+0, as the underlying RAID1 and RAID0
formats are defined in DDF. So no need to add specific RAID1+0
definitions. Also RAID1 may mean different layouts, like the "far" and
"offset" layouts, and it would mean an explosion of definitions of
RAID1+0 if you should name and standardize all of these variations of
RAID1+0 explicitely.

best regards
keld

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  reply	other threads:[~2011-02-04  9:06 UTC|newest]

Thread overview: 127+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-31  9:41 What's the typical RAID10 setup? Mathias Burén
2011-01-31 10:14 ` Robin Hill
2011-01-31 10:22   ` Mathias Burén
2011-01-31 10:36 ` CoolCold
2011-01-31 15:00   ` Roberto Spadim
2011-01-31 15:21     ` Robin Hill
2011-01-31 15:27       ` Roberto Spadim
2011-01-31 15:28         ` Roberto Spadim
2011-01-31 15:32           ` Roberto Spadim
2011-01-31 15:34             ` Roberto Spadim
2011-01-31 15:37               ` Roberto Spadim
2011-01-31 15:45             ` Robin Hill
2011-01-31 16:55         ` Denis
2011-01-31 17:31           ` Roberto Spadim
2011-01-31 18:35             ` Denis
2011-01-31 19:15               ` Roberto Spadim
2011-01-31 19:28                 ` Keld Jørn Simonsen
2011-01-31 19:35                   ` Roberto Spadim
2011-01-31 19:37                     ` Roberto Spadim
2011-01-31 20:22                     ` Keld Jørn Simonsen
2011-01-31 20:17                   ` Stan Hoeppner
2011-01-31 20:37                     ` Keld Jørn Simonsen
2011-01-31 21:20                       ` Roberto Spadim
2011-01-31 21:24                         ` Mathias Burén
2011-01-31 21:27                           ` Jon Nelson
2011-01-31 21:47                             ` Roberto Spadim
2011-01-31 21:51                               ` Roberto Spadim
2011-01-31 22:50                                 ` NeilBrown
2011-01-31 22:53                                   ` Roberto Spadim
2011-01-31 23:10                                     ` NeilBrown
2011-01-31 23:14                                       ` Roberto Spadim
2011-01-31 22:52                               ` Keld Jørn Simonsen
2011-01-31 23:00                                 ` Roberto Spadim
2011-02-01 10:01                                 ` David Brown
2011-02-01 13:50                                   ` Jon Nelson
2011-02-01 14:25                                     ` Roberto Spadim
2011-02-01 14:48                                     ` David Brown
2011-02-01 15:41                                       ` Roberto Spadim
2011-02-03  3:36                                         ` Drew
2011-02-03  8:18                                           ` Stan Hoeppner
     [not found]                                           ` <AANLkTikerSZfhMbkEvGBVyLB=wHDSHLWszoEz5As5Hi4@mail.gmail.com>
     [not found]                                             ` <AANLkTikLyR206x4aMy+veNkWPV67uF9r5dZKGqXJUEqN@mail.gmail.com>
2011-02-03 14:35                                               ` Roberto Spadim
2011-02-03 15:43                                                 ` Keld Jørn Simonsen
2011-02-03 15:50                                                   ` Roberto Spadim
2011-02-03 15:54                                                     ` Roberto Spadim
2011-02-03 16:02                                                     ` Keld Jørn Simonsen
2011-02-03 16:07                                                       ` Roberto Spadim
2011-02-03 16:16                                                       ` Roberto Spadim
2011-02-01 22:05                                     ` Stan Hoeppner
2011-02-01 23:12                                       ` Roberto Spadim
2011-02-02  9:25                                         ` Robin Hill
2011-02-02 16:00                                           ` Roberto Spadim
2011-02-02 16:06                                             ` Roberto Spadim
2011-02-02 16:07                                               ` Roberto Spadim
2011-02-02 16:10                                                 ` Roberto Spadim
2011-02-02 16:13                                                   ` Roberto Spadim
2011-02-02 19:44                                                     ` Keld Jørn Simonsen
2011-02-02 20:28                                                       ` Roberto Spadim
2011-02-02 21:31                                                         ` Roberto Spadim
2011-02-02 22:13                                                         ` Keld Jørn Simonsen
2011-02-02 22:26                                                           ` Roberto Spadim
2011-02-03  1:57                                                             ` Roberto Spadim
2011-02-03  3:05                                                         ` Stan Hoeppner
2011-02-03  3:13                                                           ` Roberto Spadim
2011-02-03  3:17                                                             ` Roberto Spadim
2011-02-01 23:35                                       ` Keld Jørn Simonsen
2011-02-01 16:02                                   ` Keld Jørn Simonsen
2011-02-01 16:24                                     ` Roberto Spadim
2011-02-01 17:56                                       ` Keld Jørn Simonsen
2011-02-01 18:09                                         ` Roberto Spadim
2011-02-01 20:16                                           ` Keld Jørn Simonsen
2011-02-01 20:32                                     ` Keld Jørn Simonsen
2011-02-01 20:58                                       ` Roberto Spadim
2011-02-01 21:04                                         ` Roberto Spadim
2011-02-01 21:18                                     ` David Brown
2011-02-01  0:58                             ` Stan Hoeppner
2011-02-01 12:50                               ` Roman Mamedov
2011-02-03 11:04                               ` Keld Jørn Simonsen
2011-02-03 14:17                                 ` Roberto Spadim
2011-02-03 15:54                                   ` Keld Jørn Simonsen
2011-02-03 18:39                                     ` Keld Jørn Simonsen
2011-02-03 18:41                                       ` Roberto Spadim
2011-02-03 23:43                                 ` Stan Hoeppner
2011-02-04  3:49                                   ` hansbkk
2011-02-04  7:06                                   ` Keld Jørn Simonsen
2011-02-04  8:27                                     ` Stan Hoeppner
2011-02-04  9:06                                       ` Keld Jørn Simonsen [this message]
2011-02-04 10:04                                         ` Stan Hoeppner
2011-02-04 11:15                                           ` hansbkk
2011-02-04 13:33                                             ` Keld Jørn Simonsen
2011-02-04 20:35                                           ` Keld Jørn Simonsen
2011-02-04 20:42                                         ` Keld Jørn Simonsen
2011-02-04 21:15                                           ` Stan Hoeppner
2011-02-04 22:05                                             ` Keld Jørn Simonsen
2011-02-04 23:03                                               ` Stan Hoeppner
2011-02-06  3:59                                                 ` Drew
2011-02-06  4:27                                                   ` Stan Hoeppner
2011-02-04 11:34                                       ` David Brown
2011-02-04 13:53                                         ` Keld Jørn Simonsen
2011-02-04 14:17                                           ` David Brown
2011-02-04 14:21                                           ` hansbkk
2011-02-06  4:02                                             ` Drew
2011-02-06  7:58                                               ` Keld Jørn Simonsen
2011-02-06 12:03                                                 ` Roman Mamedov
2011-02-06 14:30                                                   ` Roberto Spadim
2011-02-01  8:46                             ` hansbkk
2011-01-31 19:37               ` Phillip Susi
2011-01-31 19:41                 ` Roberto Spadim
2011-01-31 19:46                   ` Phillip Susi
2011-01-31 19:53                     ` Roberto Spadim
2011-01-31 22:10                       ` Phillip Susi
2011-01-31 22:14                         ` Denis
2011-01-31 22:33                           ` Roberto Spadim
2011-01-31 22:36                             ` Roberto Spadim
2011-01-31 20:23                 ` Stan Hoeppner
2011-01-31 21:59                   ` Phillip Susi
2011-01-31 22:08                     ` Jon Nelson
2011-01-31 22:38                       ` Phillip Susi
2011-02-01 10:05                         ` David Brown
2011-02-01  9:20                     ` Robin Hill
2011-02-04 16:03                       ` Phillip Susi
2011-02-04 16:22                         ` Robin Hill
2011-02-04 20:35                           ` [OT] " Phil Turmel
2011-02-04 20:35                           ` Phillip Susi
2011-02-04 21:05                           ` Stan Hoeppner
2011-02-04 21:13                             ` Roberto Spadim
2011-01-31 15:30       ` Robin Hill
2011-01-31 20:07 ` Stan Hoeppner

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