* Unable to mount btrfs partition
@ 2011-10-28 20:36 email
2011-10-28 21:09 ` Hugo Mills
0 siblings, 1 reply; 5+ messages in thread
From: email @ 2011-10-28 20:36 UTC (permalink / raw)
To: linux-btrfs
Hello!
Today I downgraded from Ubuntu's APT repo "oneiric-proposed" (which
brings some kernel 3.0.0-13) back to the standard repo "oneiric".
Now I'm not able to mount my btrfs / and /home (both on the same
partition) anymore:
device fsid SOME-UUID devid 1 transid 84229 /dev/dm-0
parent transid verify failed on 77078528 wanted 83774 found 84226
parent transid verify failed on 77078528 wanted 83774 found 84226
parent transid verify failed on 77078528 wanted 83774 found 84226
parent transid verify failed on 77078528 wanted 83774 found 84226
btrfs: open_ctree failed
The boot process drops to the initramfs shell with no btrfsck
available. I tried to boot with both the "new" 3.0.0-13 kernel and the
old 3.0.0-12 and 3.0.0-11 kernels -- no success. I'm running a live cd
right now with 3.0.0-12 and I get the above error no matter what I do:
no mount, no fsck, no nothing.
I really hope someone can help me get my data back...
Joachim
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Unable to mount btrfs partition
2011-10-28 20:36 Unable to mount btrfs partition email
@ 2011-10-28 21:09 ` Hugo Mills
2011-10-28 23:45 ` email
0 siblings, 1 reply; 5+ messages in thread
From: Hugo Mills @ 2011-10-28 21:09 UTC (permalink / raw)
To: email; +Cc: linux-btrfs
[-- Attachment #1: Type: text/plain, Size: 2311 bytes --]
On Fri, Oct 28, 2011 at 08:36:28PM +0000, email@joachim-neu.de wrote:
> Today I downgraded from Ubuntu's APT repo "oneiric-proposed" (which
> brings some kernel 3.0.0-13) back to the standard repo "oneiric".
It's odd that switching from one 3.0.0 to another would cause
something bad to happen. Did something else happen in the process,
like a reboot without a clean shutdown? (This includes power loss,
suspend and failure to resume, and Alt-SysRq-b).
> Now I'm not able to mount my btrfs / and /home (both on the same
> partition) anymore:
>
> device fsid SOME-UUID devid 1 transid 84229 /dev/dm-0
> parent transid verify failed on 77078528 wanted 83774 found 84226
> parent transid verify failed on 77078528 wanted 83774 found 84226
> parent transid verify failed on 77078528 wanted 83774 found 84226
> parent transid verify failed on 77078528 wanted 83774 found 84226
> btrfs: open_ctree failed
>
> The boot process drops to the initramfs shell with no btrfsck
> available.
It wouldn't make any difference if it were -- btrfsck doesn't
actually fix anything, I'm afraid. This error message is regrettably
generic, and covers a whole range of evils. It's possible that 3.1 may
be able to deal swith the breakage ufficiently well to allow you to
boot and copy your files.
> I tried to boot with both the "new" 3.0.0-13 kernel and
> the old 3.0.0-12 and 3.0.0-11 kernels -- no success. I'm running a
> live cd right now with 3.0.0-12 and I get the above error no matter
> what I do: no mount, no fsck, no nothing.
>
> I really hope someone can help me get my data back...
You could try using a 3.1 kernel, as I suggested above. Failing
that, in josef's git repository at [1], you will find a tool called
"restore". This should allow you to copy any files that had been
modified since your last backup. If you haven't got backups, you
*really* should look into getting some before continuing to use a
filesystem marked as EXPERIMENTAL...
Hugo.
[1] https://github.com/josefbacik/btrfs-progs
--
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
--- If you're not part of the solution, you're part ---
of the precipiate.
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Unable to mount btrfs partition
2011-10-28 21:09 ` Hugo Mills
@ 2011-10-28 23:45 ` email
2011-10-31 4:19 ` dima
2011-10-31 8:30 ` Hugo Mills
0 siblings, 2 replies; 5+ messages in thread
From: email @ 2011-10-28 23:45 UTC (permalink / raw)
To: Hugo Mills; +Cc: linux-btrfs
On Fri, 28 Oct 2011 22:09:47 +0100, Hugo Mills <hugo@carfax.org.uk>
wrote:
> On Fri, Oct 28, 2011 at 08:36:28PM +0000, email@joachim-neu.de wrote:
>> Today I downgraded from Ubuntu's APT repo "oneiric-proposed" (which
>> brings some kernel 3.0.0-13) back to the standard repo "oneiric".
>
> It's odd that switching from one 3.0.0 to another would cause
> something bad to happen. Did something else happen in the process,
> like a reboot without a clean shutdown? (This includes power loss,
> suspend and failure to resume, and Alt-SysRq-b).
I agree, but there was no power loss or anything. Maybe the fs didn't
unmount correctly or fast enough when rebooting?
>> Now I'm not able to mount my btrfs / and /home (both on the same
>> partition) anymore:
>>
>> device fsid SOME-UUID devid 1 transid 84229 /dev/dm-0
>> parent transid verify failed on 77078528 wanted 83774 found 84226
>> parent transid verify failed on 77078528 wanted 83774 found 84226
>> parent transid verify failed on 77078528 wanted 83774 found 84226
>> parent transid verify failed on 77078528 wanted 83774 found 84226
>> btrfs: open_ctree failed
>>
>> The boot process drops to the initramfs shell with no btrfsck
>> available.
>
> It wouldn't make any difference if it were -- btrfsck doesn't
> actually fix anything, I'm afraid. This error message is regrettably
> generic, and covers a whole range of evils. It's possible that 3.1
> may
> be able to deal swith the breakage ufficiently well to allow you to
> boot and copy your files.
I'll give the 3.1 kernel a try right after "restore" finished which is
running right now and doing quite a good job so far (as far as my / is
concerned, lets wait for the /home).
What do the above error messages indicate? Is there an incrementing
number for every transaction and the number of the most recent
transaction is stored somewhere and those messages occur once those
numbers are out of sync somehow? Is it possible to "just" discard the
last transactions? I would not mind, better loose a day than a month...
Why is the message there three times? Is this information stored in a
couple of backups? If so: can't I use any of the other backups
temporarily? "restore" opens the fs in a ro recovery mode somehow where
it ignores those errors. Is it possible to "force" the btrfs driver to
load the fs in this recovery mode as readonly, too?
>> I tried to boot with both the "new" 3.0.0-13 kernel and
>> the old 3.0.0-12 and 3.0.0-11 kernels -- no success. I'm running a
>> live cd right now with 3.0.0-12 and I get the above error no matter
>> what I do: no mount, no fsck, no nothing.
>>
>> I really hope someone can help me get my data back...
>
> You could try using a 3.1 kernel, as I suggested above. Failing
> that, in josef's git repository at [1], you will find a tool called
> "restore". This should allow you to copy any files that had been
> modified since your last backup. If you haven't got backups, you
> *really* should look into getting some before continuing to use a
> filesystem marked as EXPERIMENTAL...
>
> Hugo.
Thanks a lot for your help so far. I hope "restore" will do the trick,
if not I'll give kernel 3.1 a try.
Joachim
>
> [1] https://github.com/josefbacik/btrfs-progs
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Unable to mount btrfs partition
2011-10-28 23:45 ` email
@ 2011-10-31 4:19 ` dima
2011-10-31 8:30 ` Hugo Mills
1 sibling, 0 replies; 5+ messages in thread
From: dima @ 2011-10-31 4:19 UTC (permalink / raw)
To: email; +Cc: linux-btrfs
On 10/29/2011 08:45 AM, email@joachim-neu.de wrote:
>
> On Fri, 28 Oct 2011 22:09:47 +0100, Hugo Mills <hugo@carfax.org.uk> wrote:
>> On Fri, Oct 28, 2011 at 08:36:28PM +0000, email@joachim-neu.de wrote:
>>> Today I downgraded from Ubuntu's APT repo "oneiric-proposed" (which
>>> brings some kernel 3.0.0-13) back to the standard repo "oneiric".
>>
>> It's odd that switching from one 3.0.0 to another would cause
>> something bad to happen. Did something else happen in the process,
>> like a reboot without a clean shutdown? (This includes power loss,
>> suspend and failure to resume, and Alt-SysRq-b).
>
> I agree, but there was no power loss or anything. Maybe the fs didn't
> unmount correctly or fast enough when rebooting?
>
>>> Now I'm not able to mount my btrfs / and /home (both on the same
>>> partition) anymore:
>>>
>>> device fsid SOME-UUID devid 1 transid 84229 /dev/dm-0
>>> parent transid verify failed on 77078528 wanted 83774 found 84226
>>> parent transid verify failed on 77078528 wanted 83774 found 84226
>>> parent transid verify failed on 77078528 wanted 83774 found 84226
>>> parent transid verify failed on 77078528 wanted 83774 found 84226
>>> btrfs: open_ctree failed
>>>
>>> The boot process drops to the initramfs shell with no btrfsck
>>> available.
>>
>> It wouldn't make any difference if it were -- btrfsck doesn't
>> actually fix anything, I'm afraid. This error message is regrettably
>> generic, and covers a whole range of evils. It's possible that 3.1 may
>> be able to deal swith the breakage ufficiently well to allow you to
>> boot and copy your files.
>
> I'll give the 3.1 kernel a try right after "restore" finished which is
> running right now and doing quite a good job so far (as far as my / is
> concerned, lets wait for the /home).
You should definitely try 3.1. There are many improvements for btrfs.
What errors are you getting on the screen and in your logs when you try
to mount your subvolumes manually when booting from a live CD? Are / and
/home in different subvolumes by the way?
> What do the above error messages indicate?
Try to google it. It looks like pretty common error that can be caused
by a bunch of things as Hugo mentioned.
> Is there an incrementing
> number for every transaction and the number of the most recent
> transaction is stored somewhere and those messages occur once those
> numbers are out of sync somehow? Is it possible to "just" discard the
> last transactions? I would not mind, better loose a day than a month...
> Why is the message there three times? Is this information stored in a
> couple of backups? If so: can't I use any of the other backups
> temporarily? "restore" opens the fs in a ro recovery mode somehow where
> it ignores those errors. Is it possible to "force" the btrfs driver to
> load the fs in this recovery mode as readonly, too?
I don't think anything of this is possible.
~d
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Unable to mount btrfs partition
2011-10-28 23:45 ` email
2011-10-31 4:19 ` dima
@ 2011-10-31 8:30 ` Hugo Mills
1 sibling, 0 replies; 5+ messages in thread
From: Hugo Mills @ 2011-10-31 8:30 UTC (permalink / raw)
To: email; +Cc: linux-btrfs
[-- Attachment #1: Type: text/plain, Size: 3320 bytes --]
On Sat, Oct 29, 2011 at 01:45:32AM +0200, email@joachim-neu.de wrote:
>
> On Fri, 28 Oct 2011 22:09:47 +0100, Hugo Mills <hugo@carfax.org.uk>
> wrote:
> >On Fri, Oct 28, 2011 at 08:36:28PM +0000, email@joachim-neu.de wrote:
> >>Now I'm not able to mount my btrfs / and /home (both on the same
> >>partition) anymore:
> >>
> >>device fsid SOME-UUID devid 1 transid 84229 /dev/dm-0
> >>parent transid verify failed on 77078528 wanted 83774 found 84226
> >>parent transid verify failed on 77078528 wanted 83774 found 84226
> >>parent transid verify failed on 77078528 wanted 83774 found 84226
> >>parent transid verify failed on 77078528 wanted 83774 found 84226
> >>btrfs: open_ctree failed
> >>
> >>The boot process drops to the initramfs shell with no btrfsck
> >>available.
> >
> > It wouldn't make any difference if it were -- btrfsck doesn't
> >actually fix anything, I'm afraid. This error message is regrettably
> >generic, and covers a whole range of evils. It's possible that 3.1
> >may
> >be able to deal swith the breakage ufficiently well to allow you to
> >boot and copy your files.
>
> I'll give the 3.1 kernel a try right after "restore" finished which
> is running right now and doing quite a good job so far (as far as my
> / is concerned, lets wait for the /home).
>
> What do the above error messages indicate? Is there an incrementing
> number for every transaction and the number of the most recent
> transaction is stored somewhere and those messages occur once those
> numbers are out of sync somehow?
Yes, that's more or less right.
> Is it possible to "just" discard
> the last transactions? I would not mind, better loose a day than a
> month... Why is the message there three times?
The transid is stored in every single metadata block. When reading
anything from the filesystem, there are typically many metadata blocks
read, and in this case several of them have transids later than the
expected value (which will come from the superblock).
> Is this information stored in a couple of backups? If so: can't I
> use any of the other backups temporarily?
There's no explicit backups. btrfs is a copy-on-write filesystem,
which means, amongst other things, that when new metadata (or data) is
written to the FS, the old metadata is not overwritten immediately.
However, it _is_ marked as free space, and so could be overwritten at
any time. This isn't a backup in any sense of the word, and it's not
directly reachable through the FS's normal interfaces. It's entirely
down to luck whether the older blocks are still there.
> "restore" opens the fs in a ro recovery mode somehow where it
> ignores those errors. Is it possible to "force" the btrfs driver to
> load the fs in this recovery mode as readonly, too?
No, I think the reasoning is that once your FS has got to this
state, it's sufficiently badly broken that we don't want to try
recovering anything from kernel space because it's too hard, and too
many odd things could show up and crash the FS driver.
Hugo.
--
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
--- We are all lying in the gutter, but some of us are looking ---
at the stars.
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^ permalink raw reply [flat|nested] 5+ messages in thread
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2011-10-28 20:36 Unable to mount btrfs partition email
2011-10-28 21:09 ` Hugo Mills
2011-10-28 23:45 ` email
2011-10-31 4:19 ` dima
2011-10-31 8:30 ` Hugo Mills
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