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From: Chris Mason <chris.mason@oracle.com>
To: Avi Kivity <avi@redhat.com>
Cc: Ric Wheeler <rwheeler@redhat.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 10:36:55 -0400	[thread overview]
Message-ID: <1224686215.6448.49.camel@think.oraclecorp.com> (raw)
In-Reply-To: <48FF396B.1020700@redhat.com>

On Wed, 2008-10-22 at 16:32 +0200, Avi Kivity wrote:
> Ric Wheeler wrote: 
> > One key is not to replace the drives too early - you often can recover 
> > significant amounts of data from a drive that is on its last legs. 
> > This can be useful even in RAID rebuilds since with today's enormous 
> > drive capacities, you might hit a latent error during the rebuild on 
> > one of the presumed healthy drives.
> >
> > Of course, if you don't have a spare drive in your configuration, this 
> > is not practical...
> 
> Why would you have a spare drive?  That's a wasted spindle.
> 
> You want to have spare capacity, enough for one or two (or fifteen) 
> drives' worth of data.  When a drive goes bad, you rebuild into the 
> spare capacity you have.
> 

You want spare capacity that does not degrade your raid levels if you
move the data onto it.  In some configs, this will be a hot spare, in
others it'll just be free space.

-chris



  reply	other threads:[~2008-10-22 14:36 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 [this message]
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
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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