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Date: Fri, 14 Sep 2001 10:03:51 +0000
From: Pavel Machek <pavel@suse.cz>
To: John Ripley <jripley@riohome.com>
Cc: linux-kernel@vger.kernel.org, VDA <VDA@port.imtp.ilyichevsk.odessa.ua>
Subject: Re: COW fs (Re: Editing-in-place of a large file)
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Hi!

> - Keep a hash of the contents of blocks in the buffer-cache.
> - The kernel compares the hash of each block write to all blocks already
> in the buffer-cache.
> - If a duplicate is found, the kernel generates a COW link instead of
> writing the block to disk.
> 
> Obviously this would involve large amounts of CPU. I think a simple

Why? If you hashed the hashes, you could do it very fast.
								Pavel
-- 
Philips Velo 1: 1"x4"x8", 300gram, 60, 12MB, 40bogomips, linux, mutt,
details at http://atrey.karlin.mff.cuni.cz/~pavel/velo/index.html.