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From: Andreas Dilger <adilger@clusterfs.com>
To: Matt Domsch <Matt_Domsch@dell.com>
Cc: Scott Long <scott_long@adaptec.com>,
	linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: Proposed Enhancements to MD
Date: Tue, 13 Jan 2004 10:13:50 -0700	[thread overview]
Message-ID: <20040113171350.GI1437@schnapps.adilger.int> (raw)
In-Reply-To: <20040113081932.A721@lists.us.dell.com>

On Jan 13, 2004  08:19 -0600, Matt Domsch wrote:
> On Mon, Jan 12, 2004 at 08:41:54PM -0700, Scott Long wrote:
> > - DDF Metadata support: Future products will use the 'DDF' on-disk
> >    metadata scheme.  These products will be bootable by the BIOS, but
> >    must have DDF support in the OS.  This will plug into the abstraction
> >    mentioned above.
> 
> For those unfamiliar with DDF (Disk Data Format), it is a Storage
> Networking Industry Association (SNIA) project ("Common RAID DDF
> TWG"), designed to provide a single metadata format to be used by all
> the RAID vendors (hardware and software alike).  It removes vendor
> lock-in by having a metadata format that all can use, thus in theory
> you could move disks from an Adaptec hardware RAID controller to an
> LSI software RAID solution without reformatting the disks or touching
> your file systems in any way.  Dell has been championing the DDF
> concept for quite a while, and is driving vendors from which we
> purchase RAID solutions to use DDF instead of their own individual
> metadata formats.
> 
> I haven't seen the spec yet myself, but I'm lead to believe that
> DDF allows for multiple logical drives to be created across a single
> set of disks (e.g. a 10GB RAID1 LD and a 140GB RAID0 LD together on
> two 80GB spindles), as well as whole disks be used.  It has a
> mechanism to support reconstruction checkpointing, so you don't have
> to restart a reconstruct from the beginning after a reboot, but from
> where you left off.  And other useful features too that you'd expect
> in a common RAID solution.  

So, why not use EVMS and/or Device Mapper to read the DDF metadata and
set up the mappings that way?

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/


  reply	other threads:[~2004-01-13 22:18 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <40036902.8080403@adaptec.com>
2004-01-13 14:19 ` Proposed Enhancements to MD Matt Domsch
2004-01-13 17:13   ` Andreas Dilger [this message]
2004-01-13 22:26     ` Andreas Dilger
2004-01-13 18:19   ` Kevin P. Fleming
2004-01-13 18:19   ` Jeff Garzik
2004-01-13 20:29     ` Chris Friesen
2004-01-13 20:35       ` Matt Domsch
2004-01-13 21:10     ` Matt Domsch
2004-01-13 19:59 Proposed enhancements " Cress, Andrew R
  -- strict thread matches above, loose matches on Subject: below --
2004-01-13  0:34 Scott Long
2004-01-13 16:26 ` Jakob Oestergaard
     [not found]   ` <20040113201058.GD1594@srv-lnx2600.matchmail.com>
2004-01-14 19:07     ` Jakob Oestergaard
     [not found]       ` <20040114194052.GK1594@srv-lnx2600.matchmail.com>
2004-01-14 21:02         ` Jakob Oestergaard
     [not found]           ` <20040114222447.GL1594@srv-lnx2600.matchmail.com>
2004-01-15  1:42             ` Jakob Oestergaard
2004-01-13 18:21 ` mutex
2004-01-13 19:05   ` Jeff Garzik
2004-01-13 19:30     ` mutex
2004-01-13 19:43       ` Jeff Garzik
2004-01-13 20:00         ` mutex
2004-01-13 20:44   ` Scott Long
2004-01-13 18:44 ` Jeff Garzik
2004-01-13 19:01   ` John Bradford
2004-01-13 19:41   ` Matt Domsch
2004-01-13 22:10     ` Arjan van de Ven
2004-01-16  9:31     ` Lars Marowsky-Bree
2004-01-16  9:57       ` Arjan van de Ven
2004-01-13 20:41   ` Scott Long
2004-01-13 22:33     ` Jure Pečar
2004-01-13 22:44       ` Scott Long
2004-01-13 22:56       ` viro
2004-01-14 15:52     ` Kevin Corry
2004-01-13 22:42   ` Luca Berra
2004-01-13 22:06 ` Arjan van de Ven
2004-01-13 22:44   ` Wakko Warner
2004-01-13 22:34     ` Arjan van de Ven
2004-01-13 23:09     ` Andreas Steinmetz
2004-01-13 23:38       ` Wakko Warner
2004-01-14 16:16         ` Kevin Corry
2004-01-14 16:53           ` Kevin P. Fleming
2004-01-14 23:07 ` Neil Brown
2004-01-15 21:52   ` Matt Domsch
2004-01-16  9:24     ` Lars Marowsky-Bree
2004-01-16 13:43       ` Matt Domsch
2004-01-16 13:56         ` Lars Marowsky-Bree
2004-01-16 14:06           ` Christoph Hellwig
2004-01-16 14:11             ` Matt Domsch
2004-01-16 14:13               ` Christoph Hellwig

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