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From: Robert L Mathews <lists@tigertech.com>
To: linux-raid@vger.kernel.org
Subject: Re: Reassembling RAID1 after good drive was offline [newbie]
Date: Mon, 05 Jan 2015 09:25:55 -0800	[thread overview]
Message-ID: <54AAC923.1070501@tigertech.com> (raw)
In-Reply-To: <54A9B472.9090905@youngman.org.uk>

On 1/4/15 1:45 PM, Wols Lists wrote:

> It's only the other raids that have any error correction ability,
> because they use parity etc to be able to tell which set of data is correct.

In theory, yes, but in practice, they don't -- or do they? I thought
that even if you use RAID 6, md doesn't check all members on each read
request, calculate parities, and mask silent platter-level corruption by
ignoring a member spewing bad bits. It just uses parities to fill in
missing data if a member fails.

Or does it actually do error detection, and I'm confused?

-- 
Robert L Mathews, Tiger Technologies, http://www.tigertech.net/

  reply	other threads:[~2015-01-05 17:25 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-01 17:40 Reassembling RAID1 after good drive was offline [newbie] Aryeh Leib Taurog
2015-01-01 20:54 ` Robert L Mathews
2015-01-02 11:01   ` Anthonys Lists
2015-01-02 14:02     ` Aryeh Leib Taurog
2015-01-02 13:01   ` Aryeh Leib Taurog
2015-01-02 18:38     ` Robert L Mathews
2015-01-04 10:20       ` Aryeh Leib Taurog
2015-01-04 11:10         ` Peter Grandi
2015-01-04 21:07           ` Aryeh Leib Taurog
2015-01-04 21:45             ` Wols Lists
2015-01-05 17:25               ` Robert L Mathews [this message]
2015-01-05 18:54               ` NeilBrown
2015-01-07  8:30                 ` Aryeh Leib Taurog

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