All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
To: device-mapper development <dm-devel@redhat.com>
Subject: Re: dm-cache refusing to come up again after a crash
Date: Mon, 9 Dec 2013 11:34:15 +0100	[thread overview]
Message-ID: <20131209103415.GA15782@samfundet.no> (raw)
In-Reply-To: <20131209102811.GB26971@debian>

On Mon, Dec 09, 2013 at 10:28:11AM +0000, Joe Thornber wrote:
>> Well, first of all, it doesn't compile, since you use typename outside of
>> templates :-) Fixing that is easy, though. But afterwards:
> Grr, I thought that was fixed, what version of g++ are you using?

This is an Ubuntu 10.04 live CD, which was what I was having handy.
It works fine in a Debian wheezy live CD (which I switched to later).

>> So where do I want to go from there? cache_dump doesn't want to play with the
>> superblock because the checksum is bad... do I want cache_repair, then? Do I
>> want to take a backup of anything first?
> Ouch.  Could you go through what happened please?  Did dm-cache crash,
> or did the machine die for some other reason?

The machine hung. I don't know entirely why (I don't have the logs).
I rebooted, and it refused to take up the volume (this is what the original
post in this message is about). After booting to a live CD and running
cache_check and cache_dump, I was convinced there were no dirty blocks,
so I nuked the entire metadata volume (using dd from /dev/zero).

This made the machine boot again, but with tons of filesystem errors on
anything I'd written to in the last few months, so I restored from backup
(thankfully I do have working backups!). I also upgraded to 3.13-rc3 in the
hopes of fixing whatever issue in 3.12 originally caused this; however, as
reported in the other thread, this was notoriously unstable, and after the
third crash, I was back into the “won't boot, but cache_check says everything
is fine” mode.

That's the current status; it's now standing in a live CD and not doing much
useful. I miss my machine :-) (And I hope I haven't lost data again.) Will it
help if I upload a dump of the 512MB metadata volume somewhere?

/* Steinar */
-- 
Homepage: http://www.sesse.net/

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel

      reply	other threads:[~2013-12-09 10:34 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-06 15:49 dm-cache refusing to come up again after a crash Steinar H. Gunderson
2013-12-06 17:57 ` Joe Thornber
2013-12-06 19:16   ` Steinar H. Gunderson
2013-12-06 19:35     ` Steinar H. Gunderson
2013-12-06 19:53       ` Steinar H. Gunderson
2013-12-07  0:16         ` Steinar H. Gunderson
2013-12-09 10:31       ` Joe Thornber
2013-12-09 10:28     ` Joe Thornber
2013-12-09 10:34       ` Steinar H. Gunderson [this message]

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=20131209103415.GA15782@samfundet.no \
    --to=sgunderson@bigfoot.com \
    --cc=dm-devel@redhat.com \
    /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.