From: Phil Turmel <philip@turmel.org>
To: Guillaume ALLEE <guillaume.allee@gmail.com>, linux-raid@vger.kernel.org
Subject: Re: 2nd Faulty drive while rebuilding array on RAID5
Date: Sun, 25 Oct 2015 19:38:11 -0400 [thread overview]
Message-ID: <562D67E3.6050708@turmel.org> (raw)
In-Reply-To: <CABEdK7w7zjjEXXenWRK0BSziekBGhkni50y0j3t=rW2AxNkkqQ@mail.gmail.com>
Hi Guillaume,
On 10/24/2015 06:27 PM, Guillaume ALLEE wrote:
> Hi all,
>
> Context:
> On my RAID5 sdc was faulty. I bought a new HD, format it and add it to
> my raid array. However during the rebuilding sda was detected as
> faulty. Now I am not sure what to do...
Unfortunately, you are suffering from classic timeout mismatch. I've
put some links in the postscript for you to read. Most likely, your
original sdc wasn't really bad.
[trim /]
> $ mdadm --examine /dev/sd[abcdefghijklmn]3 >> raid.status
> http://pastebin.com/qaP8bvna
Something's missing. I see only sd[abcd]3. Where's the report for
/dev/sde* ?
[trim /]
> Full dmesg available at:
> http://pastebin.com/bBfcYjkg
Yes, you have WD20EARS and ST3000DM001 drive models. These are not safe
to use in raid arrays due to lack of error recovery control.
> Is there some way to re-add this disk (sda) in the array without mdadm
> thinging it is a new one ?
You need to stop the array and perform an '--assemble --force' with the
last four devices (exclude /dev/sdc). The ones that have "Raid Device"
0, 1, 2, & 3.
If that fails, show mdadm's responses in your next reply. If it works,
your array will be available to mount, but degraded. You will not be
able to add your new sdc to the array while there are unresolved UREs,
so you will need to backup your important data from the degraded array.
UREs can only be fixed by writing over them -- normally done
automatically by MD with proper drives. You will have to overwrite
those spots with zeroes or use dd_rescue to move the data to fresh
drives (with zeroes in place of the unreadable spots).
> I have seen from the wiki that I could try to recreate the array with
> --assume-clean but I want to do that only in last resort.
Do *NOT* recreate the array. (Unless you're starting over after backing
up the files from the degraded array.)
Phil
[1] http://marc.info/?l=linux-raid&m=139050322510249&w=2
[2] http://marc.info/?l=linux-raid&m=135863964624202&w=2
[3] http://marc.info/?l=linux-raid&m=135811522817345&w=1
[4] http://marc.info/?l=linux-raid&m=133761065622164&w=2
[5] http://marc.info/?l=linux-raid&m=132477199207506
[6] http://marc.info/?l=linux-raid&m=133665797115876&w=2
[7] http://marc.info/?l=linux-raid&m=142487508806844&w=3
[8] http://marc.info/?l=linux-raid&m=144535576302583&w=2
next prev parent reply other threads:[~2015-10-25 23:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-24 22:27 2nd Faulty drive while rebuilding array on RAID5 Guillaume ALLEE
2015-10-25 23:38 ` Phil Turmel [this message]
2015-10-28 20:35 ` Guillaume ALLEE
2015-10-29 12:21 ` Phil Turmel
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