From: VDA <VDA@port.imtp.ilyichevsk.odessa.ua>
To: linux-kernel@vger.kernel.org
Subject: COW fs (Re: Editing-in-place of a large file)
Date: Mon, 3 Sep 2001 00:28:18 +0300 [thread overview]
Message-ID: <318476047.20010903002818@port.imtp.ilyichevsk.odessa.ua> (raw)
In-Reply-To: <20010902152137.L23180@draal.physics.wisc.edu>
In-Reply-To: <20010902152137.L23180@draal.physics.wisc.edu>
Sunday, September 02, 2001, 11:21:37 PM, Bob McElrath wrote:
BM> I would like to take an extremely large file (multi-gigabyte) and edit
BM> it by removing a chunk out of the middle. This is easy enough by
BM> reading in the entire file and spitting it back out again, but it's
BM> hardly efficent to read in an 8GB file just to remove a 100MB segment.
BM> Is there another way to do this?
BM> Is it possible to modify the inode structure of the underlying
BM> filesystem to free blocks in the middle? (What to do with the half-full
BM> blocks that are left?) Has anyone written a tool to do something like
BM> this?
BM> Is there a way to do this in a filesystem-independent manner?
A COW fs is a far more useful and cool. A fs where a copy of a file
does not duplicate all blocks. Blocks get copied-on-write only when
copy of a file is written to. There could be even a fs compressor
which looks for and merges blocks with exactly same contents from
different files.
Maybe ext2/3 folks will play with this idea after ext3?
I'm planning to write a test program which will scan my ext2 fs and
report how many duplicate blocks with the same contents it sees (i.e
how many would I save with a COW fs)
--
Best regards,
VDA
mailto:VDA@port.imtp.ilyichevsk.odessa.ua
http://port.imtp.ilyichevsk.odessa.ua/vda/
next prev parent reply other threads:[~2001-09-02 21:29 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 ` VDA [this message]
2001-09-09 14:46 ` COW fs (Re: Editing-in-place of a large file) 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
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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