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Filesystem "somewhat" destroyed - need help for recovery/fixing

DISCUSSION Alexander Skwar 3 participants 6 messages Jun 17, 2013 – Jul 1, 2013 Btrfs file system

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#0 lore raw

Hello

I think, I somewhat destroyed my btrfs filesystem on my Ubuntu 13.04 kernel 3.8.0-25-lowlatency system. It got destroyed, because the system was hanging for some other reason and I had to remove power...

When I try to mount my filesystem (there's only one, with a few subfilesystems), the system crashes. Also btrfsck dies; always like this:

a@ask-home:~$ sudo /btrfs-progs.dev/bin/btrfsck /dev/ssd/Data 
parent transid verify failed on 33327525888 wanted 53973 found 53972
parent transid verify failed on 33327525888 wanted 53973 found 53972
Ignoring transid failure
Checking filesystem on /dev/ssd/Data
UUID: 7d2eb10f-aced-4d41-bb7f-7badbf075b6a
checking extents
checking fs roots
root 325 inode 31590 errors 400
extent buffer leak: start 33327525888 len 4096
*** Error in `btrfs check': corrupted double-linked list: 0x00000000007a2600 
***
a@ask-home:~$ /btrfs-progs.dev/bin/btrfs version
Btrfs v0.20-rc1-253-g7854c8b-dirty

btrfsck always dies with a corrupted double-linked list.

When the system crashes when I try to mount the filesystem, I get a kernel oop. Nothing in syslog, though - too fast :/ On
http://wir.myds.me/photo/photo_thumb.php?
dir=53637265656e73686f74732f4372617368206d6f756e74206274726673 or
http://imgur.com/a/UA7fF I tried to capute a few photos of the crash message. "Screenshots", of sorts...

I was able to recover most of the files with btrfs-recover. But not all of it correctly - at least one VirtualBox image is now broken.

Well - what do I do now? Could someone help, please?

Thanks a lot,
Alexander

#1 lore raw
Quoted 34 lines · Alexander Skwar

Hello

I think, I somewhat destroyed my btrfs filesystem on my Ubuntu 13.04 kernel 3.8.0-25-lowlatency system. It got destroyed, because the system was hanging for some other reason and I had to remove power...

When I try to mount my filesystem (there's only one, with a few subfilesystems), the system crashes. Also btrfsck dies; always like this:

a@ask-home:~$ sudo /btrfs-progs.dev/bin/btrfsck /dev/ssd/Data 
parent transid verify failed on 33327525888 wanted 53973 found 53972
parent transid verify failed on 33327525888 wanted 53973 found 53972
Ignoring transid failure
Checking filesystem on /dev/ssd/Data
UUID: 7d2eb10f-aced-4d41-bb7f-7badbf075b6a
checking extents
checking fs roots
root 325 inode 31590 errors 400
extent buffer leak: start 33327525888 len 4096
*** Error in `btrfs check': corrupted double-linked list: 0x00000000007a2600 
***
a@ask-home:~$ /btrfs-progs.dev/bin/btrfs version
Btrfs v0.20-rc1-253-g7854c8b-dirty

btrfsck always dies with a corrupted double-linked list.

When the system crashes when I try to mount the filesystem, I get a kernel oop. Nothing in syslog, though - too fast :/ On
http://wir.myds.me/photo/photo_thumb.php?
dir=53637265656e73686f74732f4372617368206d6f756e74206274726673 or
http://imgur.com/a/UA7fF I tried to capute a few photos of the crash message. "Screenshots", of sorts...

Quoted 5 lines

I was able to recover most of the files with btrfs-recover. But not all of it correctly - at least one VirtualBox image is now broken.

Well - what do I do now? Could someone help, please?

Pull down my tree

git://github.com/josefbacik/btrfs-progs.git

and build and run the fsck in there and see if it's a bit more friendly. Thanks,

Josef

#2 lore raw

Hello Josef

Quoted 5 lines · Josef Bacik

Pull down my tree

git://github.com/josefbacik/btrfs-progs.git

and build and run the fsck in there and see if it's a bit more friendly.

I just gave it a try, but wasn't successful, it seems… Kernel still crashes.
Maybe checkout the screenphotos at http://goo.gl/DWkRH or
http://imgur.com/a/00pTx

Thanks,

Alexander
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#3 lore raw

Hi

Quoted 6 lines · Alexander Skwar

Hello Josef

Quoted 2 lines · Josef Bacik

Pull down my tree

Quoted 8 lines
Quoted 3 lines

git://github.com/josefbacik/btrfs-progs.git

and build and run the fsck in there and see if it's a bit more friendly.

I just gave it a try, but wasn't successful, it seems… Kernel still crashes.
Maybe checkout the screenphotos at http://goo.gl/DWkRH or
http://imgur.com/a/00pTx

Any other ideas, about what I might be able to do, to revive my btrfs filesystem?

Alexander
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#4 lore raw

Re: Filesystem

Quoted 8 lines · Alexander Skwar <alexanders.mailinglists+nospam <at> gmail.com> writes:

Hi

Quoted 3 lines · On Mon, Jun 17, 2013 at 11:43 PM, Alexander Skwar…

Hello Josef

On Mon, Jun 17, 2013 at 11:21 PM, Josef Bacik <jbacik <at> fusionio.com>

Quoted 6 lines · wrote:
Quoted 6 lines
Quoted 6 lines

Pull down my tree

git://github.com/josefbacik/btrfs-progs.git

and build and run the fsck in there and see if it's a bit more

friendly.

Quoted 9 lines
Quoted 5 lines

I just gave it a try, but wasn't successful, it seems… Kernel still crashes.
Maybe checkout the screenphotos at http://goo.gl/DWkRH or
http://imgur.com/a/00pTx

Any other ideas, about what I might be able to do, to revive my btrfs filesystem?

I had the very same problem some days ago.

I have not yet found out how to fix the broken btrfs filesystem. However, I have been able to recover all my files from the filesystem and copy them to a brand new ext4 filesystem, that I am using now.

To recover files from the broken btrfs filesystem, use the program "btrfs- restore". For example, if the filesystem is on "/dev/sda1" and you want your files to be copied to the directory "/backup", then:

    $ btrfs-restore /dev/sda1 /backup

At the end, all your files should be found at the directory "/backup". If you wish, you can recreate the filesystem on "/dev/sda1" (using mkfs.btrfs or mkfs.ext4) and copy the files back to there.

Rodrigo.

#5 lore raw

Re: Filesystem

Hello Rodrigo,

Quoted 5 lines · Rodrigo Dias Cruz

I had the very same problem some days ago.

I have not yet found out how to fix the broken btrfs filesystem. However, I have been able to recover all my files from the filesystem and copy them to a brand new ext4 filesystem, that I am using now.

Well, yeah, I also tried to do "btrfs-restore". Did not work well.

It restored all files, but didn't do so in a good way. An unknown number of files got corrupted (but btrfs-restore went thru anyway). For example a VirtualBox image got destroyed and my Hamster time tracking database. And probably some more.

Quoted 1 line

At the end, all your files should be found at the directory "/backup". If

They were.

Quoted 2 lines

you wish, you can recreate the filesystem on "/dev/sda1" (using mkfs.btrfs or mkfs.ext4) and copy the files back to there.

I think, I got cured from btrfs… As of now, not ready for daily use, unless you are a real hacker.

It does have nice features, but an ugly userland (in comparison to ZFS) and is unstable with real danger of data loss.

Maybe in a few years.

Regards,

Alexander
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