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Date: Tue, 23 Apr 2002 20:48:00 +0200
From: Libor Vanek <lists@conet.cz>
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To: Alexander Viro <viro@math.psu.edu>
CC: Alvaro Figueroa <fede2@fuerzag.ulatina.ac.cr>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: Adding snapshot capability to Linux
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Alexander Viro wrote:

>You _can't_ get consistent snapshots without cooperation from fs.  LVM,
>EVMS, whatever.  Only filesystem knows what IO needs to be pushed to
>make what we have on device consistent and what IO needs to be held
>back.  Neither VFS nor device driver do not and can not have such
>knowledge - it depends both on fs layout and on implementation details.
>

My idea was to "catch" functions for writing to fs (file/metadata) and 
hold them till I copy file/metadata to snapshot. I thought that when 
done in the correct place this could work with virtualy any "normal" fs...

Libor


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