From: NeilBrown <neilb@suse.com>
To: moft@fmailbox.com, Anthony Youngman <antlists@youngman.org.uk>,
linux-raid@vger.kernel.org
Subject: Re: growing a RAID-10 array with mdadm 3.3.1+ ?
Date: Fri, 28 Oct 2016 16:47:11 +1100 [thread overview]
Message-ID: <87wpgtrpnk.fsf@notabene.neil.brown.name> (raw)
In-Reply-To: <1476211037.1004490.752738017.68CF1E3E@webmail.messagingengine.com>
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On Wed, Oct 12 2016, moft@fmailbox.com wrote:
> On Tue, Oct 11, 2016, at 11:29 AM, Anthony Youngman wrote:
>> Growing an array is pretty safe, but like anything here, it does have its dangers.
>>
>> Second, what distro are you running? Is it a systemd-based distro?
>
> Opensuse. Yes.
Specifically, which openSUSE. What version of mdadm. >
>
>> feeling is that systemd is "to blame".
>
> I have no idea why that'd be the case. That's the first time I've heard anybody suggest that.
Debian bug 840743 helped me see a possible reason.
In some cases mdadm need to remain running in the background to monitor
the reshape. Systemd doesn't like us to do that (it likes to kill
background tasks when you log off).
So on systemd installs we use a systemd service to run
mdadm --grow --continue
There was a bug in mdadm 3.3.x, fixed in 3.4, which caused that mdadm to
fail (at least in some circumstances).
The the reshape froze at the start.
>
>> > *CAN* I safely grow/expand it?
>>
>> Bugs excepted - yes you should be able to, without problems.
>
> So grouwing 'far' layouts are now supported? Do have a
> reference/source for that?
No, 'far' layout RAID10 cannot be reshaped. There are some messy issues
with making that work sensibly which I never bothered to resolve.
NeilBrown
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next prev parent reply other threads:[~2016-10-28 5:47 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-11 17:26 growing a RAID-10 array with mdadm 3.3.1+ ? moft
2016-10-11 18:29 ` Anthony Youngman
2016-10-11 18:37 ` moft
2016-10-11 18:50 ` Anthony Youngman
2016-10-28 5:47 ` NeilBrown [this message]
2016-10-11 20:26 ` Phil Turmel
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