From: Gordan Bobic <gordan@bobich.net>
To: BTRFS MAILING LIST <linux-btrfs@vger.kernel.org>
Subject: Re: Offline Deduplication for Btrfs
Date: Thu, 06 Jan 2011 12:29:02 +0000 [thread overview]
Message-ID: <4D25B58E.2080208@bobich.net> (raw)
In-Reply-To: <ig4bur$mns$1@dough.gmane.org>
Simon Farnsworth wrote:
> The basic idea is to use fanotify/inotify (whichever of the notification
> systems works for this) to track which inodes have been written to. It can
> then mmap() the changed data (before it's been dropped from RAM) and do the
> same process as an offline dedupe (hash, check for matches, call dedupe
> extent ioctl). If you've got enough CPU (maybe running with realtime privs),
> you should be able to do this before writes actually hit the disk.
I'm not convinced that racing against the disk write is the way forward
here.
As for having enough CPU to do this, a lot of modern CPUs (ARM, SPARC,
Xeon) actually have hardware crypto acceleration/offload, so calculating
checksums is fast and cheap.
Gordan
next prev parent reply other threads:[~2011-01-06 12:29 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-05 16:36 Offline Deduplication for Btrfs Josef Bacik
2011-01-05 16:36 ` [PATCH] Btrfs: add extent-same ioctl for dedup Josef Bacik
2011-01-05 17:50 ` Simon Farnsworth
2011-01-05 16:36 ` [PATCH] Btrfs-progs: add dedup functionality Josef Bacik
2011-01-05 17:42 ` Offline Deduplication for Btrfs Gordan Bobic
2011-01-05 18:41 ` Diego Calleja
2011-01-05 19:01 ` Ray Van Dolson
2011-01-05 20:27 ` Gordan Bobic
2011-01-05 20:28 ` Josef Bacik
2011-01-05 20:25 ` Gordan Bobic
2011-01-05 21:14 ` Diego Calleja
2011-01-05 21:21 ` Gordan Bobic
2011-01-05 19:46 ` Josef Bacik
2011-01-05 19:58 ` Lars Wirzenius
2011-01-05 20:15 ` Josef Bacik
2011-01-05 20:34 ` Freddie Cash
2011-01-05 21:07 ` Lars Wirzenius
2011-01-05 20:12 ` Freddie Cash
2011-01-05 20:46 ` Gordan Bobic
[not found] ` <4D250B3C.6010708@shiftmail.org>
2011-01-06 1:03 ` Gordan Bobic
2011-01-06 1:56 ` Spelic
2011-01-06 10:39 ` Gordan Bobic
2011-01-06 3:33 ` Freddie Cash
2011-01-06 1:19 ` Spelic
2011-01-06 3:58 ` Peter A
2011-01-06 10:48 ` Gordan Bobic
2011-01-06 13:33 ` Peter A
2011-01-06 14:00 ` Gordan Bobic
2011-01-06 14:52 ` Peter A
2011-01-06 15:07 ` Gordan Bobic
2011-01-06 16:11 ` Peter A
2011-01-06 18:35 ` Chris Mason
2011-01-08 0:27 ` Peter A
2011-01-06 14:30 ` Tomasz Torcz
2011-01-06 14:49 ` Gordan Bobic
2011-01-06 1:29 ` Chris Mason
2011-01-06 10:33 ` Gordan Bobic
2011-01-10 15:28 ` Ric Wheeler
2011-01-10 15:37 ` Josef Bacik
2011-01-10 15:39 ` Chris Mason
2011-01-10 15:43 ` Josef Bacik
2011-01-06 12:18 ` Simon Farnsworth
2011-01-06 12:29 ` Gordan Bobic [this message]
2011-01-06 13:30 ` Simon Farnsworth
2011-01-06 14:20 ` Ondřej Bílka
2011-01-06 14:41 ` Gordan Bobic
2011-01-06 15:37 ` Ondřej Bílka
2011-01-06 8:25 ` Yan, Zheng
-- strict thread matches above, loose matches on Subject: below --
2011-01-06 9:37 Tomasz Chmielewski
2011-01-06 9:51 ` Mike Hommey
2011-01-06 16:57 ` Hubert Kario
2011-01-06 10:52 ` Gordan Bobic
2011-01-16 0:18 Arjen Nienhuis
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