From: Roman Mamedov <rm@romanrm.net>
To: Bob Marley <bobmarley@shiftmail.org>
Cc: TM <tmjuju@yahoo.com>, linux-btrfs@vger.kernel.org
Subject: Re: 1 week to rebuid 4x 3TB raid10 is a long time!
Date: Mon, 21 Jul 2014 01:36:09 +0600 [thread overview]
Message-ID: <20140721013609.6d99c399@natsu> (raw)
In-Reply-To: <53CC1553.1020908@shiftmail.org>
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On Sun, 20 Jul 2014 21:15:31 +0200
Bob Marley <bobmarley@shiftmail.org> wrote:
> Hi TM, are you doing other significant filesystem activity during this
> rebuild, especially random accesses?
> This can reduce performances a lot on HDDs.
> E.g. if you were doing strenous multithreaded random writes in the
> meanwhile, I could expect even less than 5MB/sec overall...
I believe the problem here might be that a Btrfs rebuild *is* a strenuous
random read (+ random-ish write) just by itself.
Mdadm-based RAID would rebuild the array reading/writing disks in a completely
linear manner, and it would finish an order of magnitude faster.
--
With respect,
Roman
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next prev parent reply other threads:[~2014-07-20 19:36 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-20 8:45 1 week to rebuid 4x 3TB raid10 is a long time! TM
2014-07-20 13:53 ` Duncan
2014-07-20 14:00 ` Tomasz Torcz
2014-07-20 14:50 ` Austin S Hemmelgarn
2014-07-20 17:15 ` ashford
2014-07-20 18:21 ` TM
2014-07-20 18:23 ` TM
2014-07-20 19:15 ` Bob Marley
2014-07-20 19:36 ` Roman Mamedov [this message]
2014-07-20 19:59 ` ashford
2014-07-21 2:48 ` Duncan
2014-07-21 16:46 ` ronnie sahlberg
2014-07-21 18:31 ` Chris Murphy
2014-07-22 2:51 ` Duncan
2014-07-22 17:13 ` Chris Murphy
2014-07-24 17:19 ` Chris Murphy
2014-07-20 21:28 ` Bob Marley
2014-07-20 21:54 ` George Mitchell
2014-07-21 1:22 ` Wang Shilong
2014-07-21 14:00 ` TM
2014-07-22 1:10 ` Wang Shilong
2014-07-22 1:17 ` Wang Shilong
2014-07-22 14:43 ` TM
2014-07-22 15:30 ` Stefan Behrens
2014-07-22 20:21 ` TM
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