[HELP!] parent transid verify failed on 600755752960 wanted 757102 found 756726

[HELP!] parent transid verify failed on 600755752960 wanted 757102 found 756726

[Francesco R]

[HELP!] parent transid verify failed on 600755752960 wanted 757102 found 756726

Hi list, I've a broken btrfs filesystem to deal with can someone
please help me in recover the data?

The filesystem has been created a pair of years ago with 4 devices
with the command at #create and is mounted with #fstab options.
Recently I've added a pair of devices and made a `btrfs filesystem
balance`, after it succeded I was doing a `btrfs device delete` on
"space02" (the currently broken one) in the middle of this the power
cable has been axed.
After replacing the cable cord 'space01' is mountable, 'space02' is not.

tryed to use a backup copy of super with `btrfs-select-super` but it
fail as reported in #btrfs-select-super

please, pretty please have you suggestion on what try next?


#current kernel (vanilla + linux-vserver)
uname -a
Linux dobbia 2.6.38.8-vs2.3.0.37-rc17 #5 SMP Mon Jun 20 15:04:39 CEST
2011 x86_64 Intel(R) Core(TM) i7 CPU 950 @ 3.07GHz GenuineIntel
GNU/Linux

#create
modprobe btrfs
mkfs.btrfs -L space01 -m raid10 -d raid10 $DEVICES1
mkfs.btrfs -L space02 -m raid10 -d raid10 $DEVICES2

# fstab
/dev/sda6 /mnt/space01 btrfs
defaults,device=/dev/sda6,device=/dev/sdc6,device=/dev/sdd1,device=/dev/sde1,device=/dev/sdf6,device=/dev/sdg6
0 0
/dev/sda7 /mnt/space02 btrfs
defaults,device=/dev/sda7,device=/dev/sdb7,device=/dev/sdc7,device=/dev/sdd2,device=/dev/sde2,device=/dev/sdf7,device=/dev/sdg7
0 0

# current layout
btrfs filesystem show
failed to read /dev/sr0
Label: 'space01'  uuid: c77c6e87-fccd-4204-bd2c-d924fe06be31
        Total devices 6 FS bytes used 164.81GB
        devid    7 size 244.14GB used 56.59GB path /dev/sdf6
        devid    5 size 244.93GB used 56.59GB path /dev/sdd1
        devid    8 size 244.14GB used 56.59GB path /dev/sdg6
        devid    6 size 244.93GB used 56.59GB path /dev/sde1
        devid    4 size 244.14GB used 56.59GB path /dev/sda6
        devid    3 size 244.14GB used 56.59GB path /dev/sdc6

Label: 'space02'  uuid: f752def1-1abc-48c7-8ebb-47ba37b8ffa6
        Total devices 7 FS bytes used 172.94GB
        devid    7 size 487.65GB used 0.00 path /dev/sdf7
        devid    6 size 488.94GB used 60.25GB path /dev/sde2
        devid    5 size 488.94GB used 58.75GB path /dev/sdd2
        devid    4 size 487.65GB used 60.26GB path /dev/sda7
        devid    7 size 487.65GB used 1.50GB path /dev/sdg7
        devid    2 size 487.65GB used 58.76GB path /dev/sdb7
        devid    3 size 487.65GB used 60.26GB path /dev/sdc7

Btrfs v0.19-35-g1b444cd-dirty

# first error messages
Jun 20 14:04:35 dobbia kernel: [  806.587580] device label space02
devid 4 transid 757294 /dev/sda7
Jun 20 14:04:35 dobbia kernel: [  806.629781] device label space02
devid 2 transid 756848 /dev/sdb7
Jun 20 14:04:35 dobbia kernel: [  806.630107] device label space02
devid 3 transid 757294 /dev/sdc7
Jun 20 14:04:35 dobbia kernel: [  806.652126] device label space02
devid 5 transid 756846 /dev/sdd2
Jun 20 14:04:37 dobbia kernel: [  808.201719] device label space02
devid 6 transid 757294 /dev/sde2
Jun 20 14:04:37 dobbia kernel: [  808.218108] device label space02
devid 7 transid 756846 /dev/sdf7
Jun 20 14:04:37 dobbia kernel: [  808.218433] device label space02
devid 7 transid 757294 /dev/sdg7
Jun 20 14:04:37 dobbia kernel: [  808.218715] device label space02
devid 4 transid 757294 /dev/sda7
Jun 20 14:04:37 dobbia kernel: [  808.271797] btrfs: failed to read
the system array on sdg7
Jun 20 14:04:37 dobbia kernel: [  808.293776] btrfs: open_ctree failed
Jun 20 14:04:56 dobbia kernel: [  827.190208] device label space02
devid 4 transid 757294 /dev/sda7
Jun 20 14:04:56 dobbia kernel: [  827.254517] btrfs: failed to read
the system array on sdg7
Jun 20 14:04:56 dobbia kernel: [  827.280152] btrfs: open_ctree failed
Jun 20 14:05:01 dobbia kernel: [  832.442454] device label space02
devid 4 transid 757294 /dev/sda7
Jun 20 14:05:01 dobbia kernel: [  832.502017] btrfs: failed to read
the system array on sdg7
Jun 20 14:05:01 dobbia kernel: [  832.521492] btrfs: open_ctree failed
Jun 20 14:05:20 dobbia kernel: [  851.113237] device label space02
devid 4 transid 757294 /dev/sda7
Jun 20 14:05:20 dobbia kernel: [  851.199478] btrfs: allowing degraded mounts
Jun 20 14:05:20 dobbia kernel: [  851.563583] parent transid verify
failed on 600755752960 wanted 757102 found 756726
Jun 20 14:05:20 dobbia kernel: [  851.564146] parent transid verify
failed on 600755752960 wanted 757102 found 756726
Jun 20 14:05:20 dobbia kernel: [  851.651006] btrfs bad tree block
start 0 600859951104
Jun 20 14:05:20 dobbia kernel: [  851.671362] parent transid verify
failed on 600859955200 wanted 756926 found 756726
Jun 20 14:05:20 dobbia kernel: [  851.671636] parent transid verify
failed on 600859955200 wanted 756926 found 756726
Jun 20 14:05:20 dobbia kernel: [  851.693515] btrfs bad tree block
start 0 601053986816
Jun 20 14:05:20 dobbia kernel: [  851.693559] btrfs bad tree block
start 0 601054003200
Jun 20 14:05:20 dobbia kernel: [  851.693566] btrfs bad tree block
start 0 601054007296
Jun 20 14:05:20 dobbia kernel: [  851.693669] btrfs bad tree block
start 0 601053990912
Jun 20 14:05:20 dobbia kernel: [  851.693714] btrfs bad tree block
start 0 601053995008
Jun 20 14:05:25 dobbia kernel: [  856.642102] verify_parent_transid:
90 callbacks suppressed

#btrfs-select-super
./btrfs-select-super -s 1 /dev/sda7
using SB copy 1, bytenr 67108864
failed to read /dev/sr0
failed to read /dev/sr0
btrfs-select-super: volumes.c:1367: btrfs_read_sys_array: Assertion
`!(ret)' failed.
Aborted

Re: [HELP!] parent transid verify failed on 600755752960 wanted 757102 found 756726

[Daniel Witzel]

Welcome to the club, I have a similar issue. We pretty much have to wait for the
fsck tool to finish being developed. If possible unhook the drives and leave
them be until the tool is done. I don't know when it will be done as I am not a
developer, mearly a follower.

Re: [HELP!] parent transid verify failed on 600755752960 wanted 757102 found 756726

[Francesco R]

2011/6/21 Daniel Witzel <dannyboy48888@gmail.com>:
> Welcome to the club, I have a similar issue. We pretty much have to wait for the
> fsck tool to finish being developed. If possible unhook the drives and leave
> them be until the tool is done. I don't know when it will be done as I am not a
> developer, mearly a follower.
>

There are tools to view the metadata stored as raid10? possibly in
high level language?

I see Chris Mason stopped git commits to btrfs-progs-unstable in 2010,
there is someone working on it?

Re: [HELP!] parent transid verify failed on 600755752960 wanted 757102 found 756726

[Hugo Mills]

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On Tue, Jun 21, 2011 at 05:01:53PM +0200, Francesco R wrote:
> 2011/6/21 Daniel Witzel <dannyboy48888@gmail.com>:
> > Welcome to the club, I have a similar issue. We pretty much have to wait for the
> > fsck tool to finish being developed. If possible unhook the drives and leave
> > them be until the tool is done. I don't know when it will be done as I am not a
> > developer, mearly a follower.
> >
> 
> There are tools to view the metadata stored as raid10? possibly in
> high level language?
> 
> I see Chris Mason stopped git commits to btrfs-progs-unstable in 2010,
> there is someone working on it?

   There have been lots of commits and patches since then. The "tmp"
branch contains a bunch of commits from Chris, and the
"integration-20110616" branch in my git repository[1] contains more or
less all of the other patches that have made it to this mailing list
since.

   Sadly, none of them contain the new btrfsck code. :(

   Hugo.

[1] http://git.darksatanic.net/repo/btrfs-progs-unstable.git/

-- 
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
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Re: [HELP!] parent transid verify failed on 600755752960 wanted 757102 found 756726

[Daniel Witzel]

Well, I'm patient. Rather have a fsck that works than a fsck that may thrash the
FS so no 'gun to the head' on this one. Some feedback on RECENT progress would
be nice. Besides your merge branch Hugo (yes I tried it still no cigar...) it's
been ghost since December 2010.

Re: [HELP!] parent transid verify failed on 600755752960 wanted 757102 found 756726

[Andrej Podzimek]

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Hello,

I am facing the same issue on a Btrfs RAID0 with 2 drives:

	Label: 'root'  uuid: 1e26b203-fc1e-4ebf-9551-451bd34d3ac4
	        Total devices 2 FS bytes used 36.14GB
	        devid    1 size 80.43GB used 41.65GB path /dev/sda6
	        devid    2 size 80.43GB used 41.63GB path /dev/sdb6

	Btrfs v0.19-36-g70c6c10-dirty

Tried btrfs-select-super -s 1 /dev/sd[ab]6, but that does not help at all. On both drives, its standard output is identical:

	parent transid verify failed on 576901120 wanted 70669 found 70755
	btrfs-select-super: disk-io.c:412: find_and_setup_root: Assertion `!(!root->node)' failed.
	using SB copy 1, bytenr 67108864

This is the first error message from dmesg:

	[  156.617407] parent transid verify failed on 576901120 wanted 70669 found 70755
	[  156.617504] parent transid verify failed on 576901120 wanted 70669 found 70755
	[  156.635322] btrfs: open_ctree failed

The problem occurred shortly after this issue: http://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg10618.html The machine booted (and worked normally) at least ten times between the error message and the current problem.

The kernel version was 2.6.39.1 when the first BUG message appeared in dmesg. I downgraded to 2.6.38.8 after that and everything seemed to work fine ... up to now.

Any suggestions? ;-) I can always restore the data from another machine with identical installation. But first of all I'd like to understand this problem and know whether it can be dealt with somehow.

Andrej


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