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From: NeilBrown <neilb@suse.de>
To: Joe Lawrence <joe.lawrence@stratus.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: LVM RAID1 syncing component
Date: Thu, 27 Nov 2014 07:41:58 +1100	[thread overview]
Message-ID: <20141127074158.2a3472f3@notabene.brown> (raw)
In-Reply-To: <alpine.DEB.2.02.1411242255300.12886@jlaw-desktop.mno.stratus.com>

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On Mon, 24 Nov 2014 23:07:32 -0500 Joe Lawrence <joe.lawrence@stratus.com>
wrote:

> Does anyone know how its possible to determine which side of an LVM RAID 1 
> is the stale partner during RAID resync?
> 
> In ordinary MD RAID, I believe you can check 
> /sys/block/md0/md/dev-XXX/state,

Why do you believe that?

During a resync (after an unclean shutdown) the devices are indistinguishable.
RAID1 reads all drives and if there is a difference it chooses one data block
to write to the others - always the one with the lowest index number.

So with md or LVM it is the same: first "first" is "copied" to the "second".

NeilBrown


>                                  but LVM RAID seems to hide those files 
> when leveraging the MD code.  I've looked though pvs/vgs/lvs manpages, but 
> can't figure anything out there either.
> 
> Thanks,
> 
> -- Joe
> --
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  parent reply	other threads:[~2014-11-26 20:41 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-25  4:07 LVM RAID1 syncing component Joe Lawrence
2014-11-26  5:42 ` Chris Murphy
2014-11-26 13:20   ` Joe Lawrence
2014-11-26 20:41 ` NeilBrown [this message]
2014-11-29 15:26   ` Peter Grandi
2014-12-01 23:28     ` NeilBrown
2014-12-01 21:19   ` Joe Lawrence
2014-12-01 21:27     ` Joe Lawrence
2014-12-01 21:41     ` NeilBrown
2014-12-02 19:05       ` Joe Lawrence

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