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)
Date: Fri, 14 Sep 2001 10:03:51 +0000 [thread overview]
Message-ID: <20010914100350.C35@toy.ucw.cz> (raw)
In-Reply-To: <20010902152137.L23180@draal.physics.wisc.edu> <318476047.20010903002818@port.imtp.ilyichevsk.odessa.ua> <3B9B80E2.C9D5B947@riohome.com>
In-Reply-To: <3B9B80E2.C9D5B947@riohome.com>; from jripley@riohome.com on Sun, Sep 09, 2001 at 03:46:58PM +0100
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.
next prev parent reply other threads:[~2001-09-17 22:37 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-09-02 20:21 Editing-in-place of a large file Bob McElrath
2001-09-02 21:28 ` COW fs (Re: Editing-in-place of a large file) VDA
2001-09-09 14:46 ` John Ripley
2001-09-09 16:30 ` John Ripley
2001-09-10 2:43 ` Daniel Phillips
2001-09-10 2:58 ` David Lang
2001-09-09 17:41 ` Xavier Bestel
2001-09-10 1:29 ` John Ripley
2001-09-10 6:45 ` Ragnar Kjørstad
2001-09-14 10:06 ` Pavel Machek
2001-09-10 11:11 ` Ihar Filipau
2001-09-10 16:10 ` Kari Hurtta
2001-09-14 10:03 ` Pavel Machek [this message]
2001-09-10 9:28 ` VDA
2001-09-10 9:35 ` John P. Looney
2001-09-02 21:30 ` Editing-in-place of a large file Ingo Oeser
2001-09-03 0:59 ` Larry McVoy
2001-09-03 1:24 ` Ingo Oeser
2001-09-03 1:31 ` Alan Cox
2001-09-03 1:50 ` Ingo Oeser
2001-09-03 10:48 ` Alan Cox
2001-09-03 14:31 ` Daniel Phillips
2001-09-03 14:46 ` Bob McElrath
2001-09-03 14:54 ` Alan Cox
2001-09-03 15:42 ` Doug McNaught
2001-09-03 15:11 ` Richard Guenther
2001-09-03 21:19 ` Ben Ford
2001-09-03 4:27 ` Bob McElrath
2001-09-03 1:30 ` Daniel Phillips
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