From: Neil Brown <neilb@suse.de>
To: landman@scalableinformatics.com
Cc: linux-raid@vger.kernel.org
Subject: Re: Ok, dumb question time ...
Date: Fri, 8 Oct 2010 15:54:48 +1100 [thread overview]
Message-ID: <20101008155448.19d46db6@notabene> (raw)
In-Reply-To: <4CAE9C13.3060002@scalableinformatics.com>
On Fri, 08 Oct 2010 00:20:35 -0400
Joe Landman <landman@scalableinformatics.com> wrote:
> Not having much luck with this. Let me explain ...
>
> Imagine we have a RAID1 with 3 elements. It was originally a RAID1 with
> 2 elements, and we added a 3rd using
>
> mdadm /dev/md0 --add /dev/loop1
>
> What I want to do is conceptually very simple. I want to permanently
> remove loop1, without having the array become dirty, or degraded. That
> is, I would like
>
> mdadm /dev/md0 --fail /dev/loop1 --remove /dev/loop1
>
> to result in a clean array with two members.
>
> It doesn't. The array is marked as being in the "clean, degraded"
> state. Which, as it is the root file system array, has the unfortunate
> side effect of not allowing the RAID1 to properly assemble at boot (that
> degraded state).
>
> So ... can I force the array to either remove the extra unneeded loop1
> device, and update its metadata properly ... or force it into a clean,
> active state without the loop1 device, or force the assembly on boot to
> occur regardless of what it thinks it should have?
>
> This is quite disconcerting ... I thought it would be simple.
It is.
You want the array to think that it only has two devices?
mdadm --grow /dev/md0 --raid-devices=2
Done.
NeilBrown
next prev parent reply other threads:[~2010-10-08 4:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-08 4:20 Ok, dumb question time Joe Landman
2010-10-08 4:54 ` Neil Brown [this message]
2010-10-08 5:00 ` Joe Landman
2010-10-08 18:01 ` CoolCold
2010-10-08 18:07 ` Joe Landman
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