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Date: Fri, 31 Oct 2003 00:03:08 -0800
From: Andrew Morton <akpm@osdl.org>
To: Nuno Silva <nuno.silva@vgertech.com>
Cc: ahuisman@cistron.nl, linux-kernel@vger.kernel.org
Subject: Re: READAHEAD
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Nuno Silva <nuno.silva@vgertech.com> wrote:
>
> >> Before, i never had to set readahead so high
> >> Please could you tell me, what is going on here ?
> > 
> > 
> > Lots of people have been reporting this.  It's rather weird.
> > 
> 
> I know nothing about this but, FWIW, I think that what changed where the 
> units. With 2.4 you specify sectors, with 2.6 you specify bytes.
> 
> So, having -a8, in 2.4, is the same as having -a$((8*512)) [it's 4096 
> :)], in 2.6.
> 

No, everything seems OK.  Both `hdparm -a' and `blockdev --setra' are
operating in units of 512 bytes.