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From: "Pádraig Brady" <P@draigBrady.com>
To: Andi Kleen <andi@firstfloor.org>, Jim Meyering <jim@meyering.net>,
	linux-btrfs@vger.kernel.org, bug-coreutils@gnu.org,
	Giuseppe Scrivano <gscrivano@gnu.org>, Chris Mason <chris.mason@
Subject: Re: BTRFS file clone support for cp
Date: Fri, 31 Jul 2009 00:28:49 +0100	[thread overview]
Message-ID: <4A722CB1.80404@draigBrady.com> (raw)
In-Reply-To: <20090730180515.GB7541@mail.oracle.com>

Joel Becker wrote:
> 	In some sense, using btrfs, nilfs2i, ocfs2 with refcount trees
> enabled, or any other CoW-ish filesystem is a tacit approval of the
> delayed ENOSPC.  The same can be said of "thin provisioning" LUNs.
> However, the other concerns are still valid.  A user invoking vanilla
> cp(1) expects two independent storage regions for the data.
> 	(Oh, and what about future support of de-duping in filesystems?
> :-)

I maintain an app to de-dupe at http://www.pixelbeat.org/fslint/
and I'll be adding reflink support as soon as it becomes available.
=46rom a filesystem point of view, one thing that would help speed
this up (and many other things like rsync etc.) would be to allow
one to associate say a sha-3 hash or whatever with the file, which
the filesystem would automatically clear when the file data changes.
So in general having a special set of extended attributes that
were auto cleared on file modification would be very useful for
lots of stuff.

cheers,
P=E1draig.
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  reply	other threads:[~2009-07-30 23:28 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <87d47o3fip.fsf@master.homenet>
     [not found] ` <4A6CEA48.5050208@draigBrady.com>
     [not found]   ` <8763defuvq.fsf@meyering.net>
     [not found]     ` <87ws5tvrq8.fsf@master.homenet>
2009-07-27 23:40       ` BTRFS file clone support for cp Pádraig Brady
2009-07-28 20:06         ` Giuseppe Scrivano
2009-07-29 13:01           ` Chris Mason
2009-07-29 14:14             ` Pádraig Brady
2009-07-29 16:10               ` Chris Mason
2009-07-29 16:18                 ` Chris Mason
2009-07-29 18:14                 ` Pádraig Brady
2009-07-30  0:57                   ` Joel Becker
2009-07-30  7:39                     ` Jim Meyering
2009-07-30  8:21                       ` Joel Becker
2009-07-30  8:40                       ` Pádraig Brady
2009-07-30 16:28                         ` Ric Wheeler
2009-07-30 16:48                           ` Jim Meyering
2009-07-30  9:26                       ` Andi Kleen
2009-07-30 10:02                         ` Pádraig Brady
2009-07-30 10:16                         ` Jim Meyering
2009-07-30 10:21                           ` Tomasz Chmielewski
2009-07-30 10:54                           ` Andi Kleen
2009-07-30 18:05                             ` Joel Becker
2009-07-30 23:28                               ` Pádraig Brady [this message]
     [not found]         ` <87k51r9sxh.fsf@master.homenet>
     [not found]           ` <4A70C4E0.9030104@draigBrady.com>
2009-07-30 17:28             ` Giuseppe Scrivano

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