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From: Martin <m_btrfs@ml1.co.uk>
To: linux-btrfs@vger.kernel.org
Subject: Re: ditto blocks on ZFS
Date: Thu, 22 May 2014 00:05:26 +0100	[thread overview]
Message-ID: <lljbfo$6vm$1@ger.gmane.org> (raw)
In-Reply-To: <1795587.Ol58oREtZ7@xev>

Very good comment from Ashford.


Sorry, but I see no advantages from Russell's replies other than for a
"feel-good" factor or a dangerous false sense of security. At best,
there is a weak justification that "for metadata, again going from 2% to
4% isn't going to be a great problem" (storage is cheap and fast).

I thought an important idea behind btrfs was that we avoid by design in
the first place the very long and vulnerable RAID rebuild scenarios
suffered for block-level RAID...


On 21/05/14 03:51, Russell Coker wrote:
> Absolutely. Hopefully this discussion will inspire the developers to
> consider this an interesting technical challenge and a feature that
> is needed to beat ZFS.

Sorry, but I think that is completely the wrong reasoning. ...Unless
that is you are some proprietary sales droid hyping features and big
numbers! :-P


Personally I'm not convinced we gain anything beyond what btrfs will
eventually offer in any case for the n-way raid or the raid-n Cauchy stuff.

Also note that usually, data is wanted to be 100% reliable and
retrievable. Or if that fails, you go to your backups instead. Gambling
"proportions" and "importance" rather than *ensuring* fault/error
tolerance is a very human thing... ;-)


Sorry:

Interesting idea but not convinced there's any advantage for disk/SSD
storage.


Regards,
Martin





  reply	other threads:[~2014-05-21 23:05 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-16  3:07 ditto blocks on ZFS Russell Coker
2014-05-17 12:50 ` Martin
2014-05-17 14:24   ` Hugo Mills
2014-05-18 16:09   ` Russell Coker
2014-05-19 20:36     ` Martin
2014-05-19 21:47       ` Brendan Hide
2014-05-20  2:07         ` Russell Coker
2014-05-20 14:07           ` Austin S Hemmelgarn
2014-05-20 20:11             ` Brendan Hide
2014-05-20 14:56           ` ashford
2014-05-21  2:51             ` Russell Coker
2014-05-21 23:05               ` Martin [this message]
2014-05-22 11:10                 ` Austin S Hemmelgarn
2014-05-22 22:09               ` ashford
2014-05-23  3:54                 ` Russell Coker
2014-05-23  8:03                   ` Duncan
2014-05-21 23:29           ` Konstantinos Skarlatos
  -- strict thread matches above, loose matches on Subject: below --
2014-05-22 15:28 Tomasz Chmielewski

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