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From: Christian Borntraeger <borntraeger@de.ibm.com>
Organization: IBM
To: David Newall <davidn@davidnewall.com>
Subject: Re: defrag deployment status (was Re: [PATCH] ext4: allow defrag (EXT4_IOC_MOVE_EXT) in 32bit compat mode)
Date: Mon, 8 Mar 2010 17:00:57 +0100
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Cc: Jeff Garzik <jeff@garzik.org>, linux-ext4@vger.kernel.org,
       linux-kernel@vger.kernel.org, Akira Fujita <a-fujita@rs.jp.nec.com>
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Am Montag 08 März 2010 16:33:46 schrieb David Newall:
> Christian Borntraeger wrote:
> > Some bigger things are missing in the e4defrag tool:
> > ...
> > - overall layout considerations (e.g. putting files close to its directory or
> >   use the atime to move often used files to the beginning of a disk etc.)
> 
> Shouldn't oft-used files be placed closer to the middle?  If you place 
> them at the beginning of the file, it's only possible for the head-stack 
> to be close to the file from the inner direction.  Place them in the 
> middle and it's possible for the head-stack to be close from the outer 
> direction, too, which sounds like a doubling of probability.  It seems 
> that it's the least frequently used files that should be placed at one 
> end of the disk or the other.
> 

Maybe. This was just an example of things that you can come
up with and which are not yet possible up in e4defrag. 

Christian