From: Phil Turmel <philip@turmel.org>
To: "Peckins, Steven E" <speckins@illinois.edu>
Cc: "linux-raid@vger.kernel.org" <linux-raid@vger.kernel.org>
Subject: Re: RAID6 recovery with 6/9 drives out-of-sync
Date: Wed, 1 Jun 2016 08:06:58 -0400 [thread overview]
Message-ID: <574ECFE2.9050602@turmel.org> (raw)
In-Reply-To: <5D9C8773-D76E-409F-8961-41EB3ACD177A@illinois.edu>
On 06/01/2016 07:32 AM, Peckins, Steven E wrote:
>
> On May 31, 2016, at 2:19 PM, Phil Turmel <philip@turmel.org> wrote:
>
>> On 05/30/2016 10:43 PM, Peckins, Steven E wrote:
>>>
>>> The component devices in the array are supposed to be multipath devices (dm-multipath), but for some reason, when the server was restarted, md grabbed both dm-* components and raw devices. I *think* that this is what caused the problem.
>>
>> Quite possible. You probably need a DEVICES clause in your mdadm.conf
>> to exclude the raw devices from the arrays.
>
> I had a typo in the DEVICE glob for the system disks (/dev/sd[ab]* instead of /dev/sd[ab][12]).
Understood, but be aware that if you have to hotswap one of these system
devices, they may not get the sda or sdb name, preventing a re-add or a
replacement from joining the array.
Since you are having to use /dev/mapper entries for some arrays,
consider using /dev/disk/by*/ symlinks for your system arrays.
>>> I'm seeking advice on how to proceed at this point. If more information is required, please ask.
>>
>> Hmmm. The partial success on mdadm --force suggests trying that again.
>> Possible with --force twice on the command line.
>>
>> Forced assembly is precisely what you need -- don't despair and attempt
>> anything else.
>
> Repeating the command was not successful; it is still reporting "/dev/md10 assembled from 5 drives and 1 spare - not enough to start the array." Four drives are listed as “possibly out of date." I assume those are the four that are not being incorporated.
>
> Output from --assemble --force 1x and 2x: http://pastebin.com/k1dT2zYC
{ In the future, please paste these in-line so the archives will have
them. The size limit for this list is ~ 100k. }
I vaguely recall a bug in forced reassembly for many out-of-date drives.
Please clone and build the latest mdadm userspace[1] and run that mdadm
binary for the forced assembly. Also show the portion of dmesg that
corresponds to the attempt.
Phil
[1] https://github.com/neilbrown/mdadm
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next prev parent reply other threads:[~2016-06-01 12:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-31 2:43 RAID6 recovery with 6/9 drives out-of-sync Peckins, Steven E
2016-05-31 19:19 ` Phil Turmel
2016-06-01 11:32 ` Peckins, Steven E
2016-06-01 12:06 ` Phil Turmel [this message]
2016-06-01 13:16 ` Peckins, Steven E
2016-06-01 13:22 ` Phil Turmel
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