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From: Tomasz Torcz <tomek@pipebreaker.pl>
To: linux-btrfs@vger.kernel.org
Subject: Re: Offline Deduplication for Btrfs
Date: Thu, 6 Jan 2011 15:30:20 +0100	[thread overview]
Message-ID: <20110106143019.GB14674@mother> (raw)
In-Reply-To: <4D251888.7060508@shiftmail.org>

On Thu, Jan 06, 2011 at 02:19:04AM +0100, Spelic wrote:
> >CPU can handle considerably more than 250 block hashings per
> >second. You could argue that this changes in cases of sequential
> >I/O on big files, but a 1.86GHz GHz Core2 can churn through
> >111MB/s of SHA256, which even SSDs will struggle to keep up with.
>=20
> A normal 1TB disk with platters can do 130MB/sec sequential, no probl=
ems.
> A SSD can do more like 200MB/sec write 280MB/sec read sequential or
> random and is actually limited only by the SATA 3.0gbit/sec but soon
> enough they will have SATA/SAS 6.0gbit/sec.

  By =E2=80=9Csoon enough=E2=80=9D you really meant =E2=80=9Ca year ago=
=E2=80=9D, I think:
http://www.anandtech.com/show/3812/the-ssd-diaries-crucials-realssd-c30=
0
Current 6Gbps SSD are doing 415 MB/s sequential:
http://www.anandtech.com/show/4086/microns-realssd-c400-uses-25nm-nand-=
at-161gb-offers-415mbs-reads
or even claim 550MB/s:
http://www.anandtech.com/show/4100/ocz-vertex-pro-3-demo-worlds-first-s=
andforce-sf2000
(funny bit: Sandforce SSD controllers dedup internally).=20

  Anyway, 6Gbps is not a future tale, but something long available.
And not the fastest kids on the block:  currently build filesystems
must deal storage providing many gigabytes per second.  Think
of massive disk arrays or stuff like Oracle F5100, claiming
12.8GB/sec read and ~10GB/s write (in one rack unit).

--=20
Tomasz Torcz                 "God, root, what's the difference?"
xmpp: zdzichubg@chrome.pl         "God is more forgiving."

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  parent reply	other threads:[~2011-01-06 14:30 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 [this message]
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
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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