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From: Avi Kivity <avi@redhat.com>
To: Ric Wheeler <rwheeler@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>,
	Stephan von Krawczynski <skraw@ithnet.com>,
	Christoph Hellwig <hch@infradead.org>, jim owens <jowens@hp.com>,
	linux-btrfs@vger.kernel.org
Subject: Re: Some very basic questions
Date: Wed, 22 Oct 2008 17:39:04 +0200	[thread overview]
Message-ID: <48FF4918.6070600@redhat.com> (raw)
In-Reply-To: <48FF45EE.7010001@redhat.com>

Ric Wheeler wrote:
> I think that the btrfs plan is still to push more complicated RAID 
> schemes off to MD (RAID6, etc) so this is an issue even with a JBOD. 
> It will be interesting to map out the possible ways to use built in 
> mirroring, etc vs the external RAID and actually measure the utilized 
> capacity and performance (online & during rebuilds).

That's leaving a lot of performance and features on the table, IMO.  We 
definitely want to have metadata and small files using mirroring 
(perhaps even three copies for some metadata).  Use RAID[56] for large 
files.  Perhaps even start files at RAID1, and have the scrubber convert 
them to RAID[56] when it notices they are only ever read.  Keep 
temporary or unimportant files at RAID0.  Play games with asymmetric 
setups (small fast disks + large slow disks). etc etc etc.

Delegating things to MD throws out a lot of metadata so these things 
become impossible.

-- 
error compiling committee.c: too many arguments to function


  parent reply	other threads:[~2008-10-22 15:39 UTC|newest]

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-21 11:23 Some very basic questions Stephan von Krawczynski
2008-10-21 12:13 ` Andi Kleen
2008-10-21 14:22   ` Stephan von Krawczynski
2008-10-21 15:34     ` jim owens
2008-10-22 11:36       ` Stephan von Krawczynski
2008-10-22 12:15         ` Avi Kivity
2008-10-22 13:03           ` Ric Wheeler
2008-10-22 13:13             ` Chris Mason
2008-10-22 13:16             ` Avi Kivity
2008-10-21 13:20 ` jim owens
2008-10-21 17:01   ` Stephan von Krawczynski
2008-10-21 17:15     ` Christoph Hellwig
2008-10-21 17:31       ` Ric Wheeler
2008-10-22 12:27         ` Stephan von Krawczynski
2008-10-22 13:15           ` Chris Mason
2008-10-22 13:27             ` Ric Wheeler
2008-10-22 14:32               ` Avi Kivity
2008-10-22 14:36                 ` Chris Mason
2008-10-22 14:40                   ` Avi Kivity
2008-10-22 14:46                 ` Ric Wheeler
2008-10-22 14:54                   ` Avi Kivity
2008-10-22 15:02                     ` Ric Wheeler
2008-10-22 15:13                       ` Avi Kivity
2008-10-22 15:25                         ` Ric Wheeler
2008-10-22 15:33                           ` Chris Mason
2008-10-22 15:43                             ` Avi Kivity
2008-10-22 15:54                               ` Ric Wheeler
2008-10-22 18:28                                 ` Avi Kivity
2008-10-22 15:39                           ` Avi Kivity [this message]
2008-10-22 13:52             ` Stephan von Krawczynski
2008-10-22 15:56               ` Michel Salim
2008-10-22 16:56                 ` jim owens
2008-10-23  9:47                 ` Stephan von Krawczynski
2008-10-22 11:40       ` Stephan von Krawczynski
2008-10-21 13:59 ` Chris Mason
2008-10-21 16:09   ` Andi Kleen
2008-10-22 11:43     ` Stephan von Krawczynski
2008-10-21 16:27   ` Stephan von Krawczynski
2008-10-21 16:59     ` Andi Kleen
2008-10-22 11:46       ` Stephan von Krawczynski
2008-10-21 17:49     ` Chris Mason
2008-10-22 12:19       ` Stephan von Krawczynski
2008-10-22 12:48         ` Jeff Schroeder
2008-10-22 14:02           ` Stephan von Krawczynski
2008-10-22 13:50         ` Chris Mason
2008-10-22 14:04           ` Matthias Wächter
2008-10-22 14:32             ` Ric Wheeler
2008-10-22 14:44               ` jim owens
2008-10-24  8:42           ` Chris Samuel
2008-10-24  8:39         ` Chris Samuel
2008-10-21 20:54   ` Eric Anopolsky
2008-10-21 22:18     ` Ric Wheeler
2008-10-22  2:29       ` Eric Anopolsky
2008-10-22 10:42         ` Ric Wheeler
2008-10-22 10:53           ` Tejun Heo
2008-10-22 12:57             ` Ric Wheeler
2008-10-22 12:57             ` Ric Wheeler
2008-10-22 13:15               ` Tejun Heo
2008-10-22 13:19                 ` Chris Mason
2008-10-22 13:38                   ` Ric Wheeler
2008-10-22 13:59                     ` Chris Mason
2008-10-22 14:23                       ` Ric Wheeler
2008-10-22 13:23                 ` Ric Wheeler
2008-10-22 16:14                   ` Tejun Heo
2008-10-22 16:34                     ` Ric Wheeler
2008-10-23  3:59                       ` Tejun Heo
2008-10-22 18:32                     ` Avi Kivity
2008-10-22 19:13                       ` jim owens
2008-10-22 19:22                         ` Avi Kivity
2008-10-22 19:59                       ` Ric Wheeler
2008-10-22 21:31                     ` Eric Anopolsky
2008-10-22 21:56                       ` Ric Wheeler
  -- strict thread matches above, loose matches on Subject: below --
2008-10-21 17:37 calin
2008-10-21 20:08 ` jim owens
2008-10-22  7:15   ` Avi Kivity
2008-10-22 14:13     ` jim owens
2008-10-22 14:25       ` Avi Kivity
2008-10-22 14:35 dbz
2008-10-27 15:43 ` Stephan von Krawczynski

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