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Date: Wed, 14 Nov 2001 12:47:53 -0800
From: Mike Fedyk <mfedyk@matchmail.com>
To: Erik Tews <erik.tews@gmx.net>
Cc: linux-kernel@vger.kernel.org
Subject: Re: linux readahead setting?
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On Wed, Nov 14, 2001 at 09:41:22PM +0100, Erik Tews wrote:
> On Wed, Nov 14, 2001 at 12:26:20PM -0800, Mike Fedyk wrote:
> > At which level do you want the read ahead?
> > 
> > If you read ahead at the block level, you may not get data for the file you
> > want because of fragmentation.  This is especially true with long running
> > Reiser file systems.
> 
> I think fragmentation will be no problem, because this filesystem
> contains only one file.
> 
> Readahead should be done on filesystem or block-level. Not on disklevel.
> I can tune that with lvm, but I was not sure if a bigger readahead-value
> is that what I want.

Block and disk are conceptually the same in this instance because neither of
them know if the read ahead is going to get the next blocks for the file
being read or not...

In most cases, block=disk, except for lvm and raid...

Mike
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