From: Andreas Klauer <Andreas.Klauer@metamorpher.de>
To: Patrick Tschackert <Killing-Time@gmx.de>
Cc: linux-raid@vger.kernel.org
Subject: Re: problems with dm-raid 6
Date: Sun, 20 Mar 2016 23:37:27 +0100 [thread overview]
Message-ID: <20160320223727.GA29895@EIS> (raw)
In-Reply-To: <trinity-dd5fc296-8c28-4b99-85de-889a495e6956-1458510296940@3capp-gmx-bs09>
On Sun, Mar 20, 2016 at 10:44:57PM +0100, Patrick Tschackert wrote:
> After rebooting the system, one of the harddisks was missing from my md raid 6 (the drive was /dev/sdf), so i rebuilt it with a hotspare that was already present in the system.
> I physically removed the "missing" /dev/sdf drive after the restore and replaced it with a new drive.
Exact commands involved for those steps?
mdadm --examine output for your disks?
> $ cat /sys/block/md0/md/mismatch_cnt
> 311936608
Basically the whole array out of whack.
This is what you get when you use --create --assume-clean on disks
that are not actually clean... or if you somehow convince md to
integrate a disk that does not have valid data on, for example
because you copied partition table and md metadata - but not
everything else - using dd.
Something really bad happened here and the only person who
can explain it, is probably yourself.
Your best bet is that the data is valid on n-2 disks.
Use overlay https://raid.wiki.kernel.org/index.php/Recovering_a_failed_software_RAID#Making_the_harddisks_read-only_using_an_overlay_file
Assemble the overlay RAID with any 2 disks missing (try all combinations) and see if you get valid data.
Regards
Andreas Klauer
next prev parent reply other threads:[~2016-03-20 22:37 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <trinity-235b76ed-571d-4615-b6f7-b4d5ed6a116d-1458509365312@3capp-gmx-bs09>
2016-03-20 21:44 ` problems with dm-raid 6 Patrick Tschackert
2016-03-20 22:37 ` Andreas Klauer [this message]
2016-03-21 12:42 ` Phil Turmel
2016-03-21 13:27 ` Andreas Klauer
2016-03-21 21:26 ` Chris Murphy
2016-03-21 21:38 ` Andreas Klauer
2016-03-21 21:46 ` Chris Murphy
2016-03-21 22:42 ` Patrick Tschackert
2016-03-21 22:54 ` Adam Goryachev
2016-03-21 23:15 ` Andreas Klauer
2016-03-21 23:48 ` Adam Goryachev
2016-03-21 23:04 ` Andreas Klauer
2016-03-22 3:53 ` Chris Murphy
2016-03-22 4:22 ` Chris Murphy
2016-03-21 22:06 Patrick Tschackert
-- strict thread matches above, loose matches on Subject: below --
2016-03-21 22:19 Patrick Tschackert
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160320223727.GA29895@EIS \
--to=andreas.klauer@metamorpher.de \
--cc=Killing-Time@gmx.de \
--cc=linux-raid@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.