Re: Rebuilding 24TB Raid5 array (was btrfs corruption: parent transid verify failed + open_ctree failed)

[Marc MERLIN <marc@merlins.org>]

On Mon, Apr 04, 2022 at 02:46:57PM -0400, Josef Bacik wrote:
> Ok now that I've learned how to read, the real problem is the extent
> tree is fucked.  The chunk tree isn't happy, but it appears to be sane
> enough to proceed, which is good because that could be unfun to
> restore.
> 
> Good news is the extent tree is easily re-buildable, lets use
> 
> btrfs check --init-extent-tree /dev/whatever
> 
> and let that baby do its thing.  Hopefully that rebuilds everything
> and you'll be good to go.  Thanks,

Thanks for the suggestion, sadly it's not that simple:

gargamel:~# btrfs check --init-extent-tree  /dev/mapper/dshelf1a
WARNING:

	Do not use --repair unless you are advised to do so by a developer
	or an experienced user, and then only after having accepted that no
	fsck can successfully repair all types of filesystem corruption. Eg.
	some software or hardware bugs can fatally damage a volume.
	The operation will start in 10 seconds.
	Use Ctrl-C to stop it.
10 9 8 7 6 5 4 3 2 1
Starting repair.
Opening filesystem to check...
parent transid verify failed on 22216704 wanted 1600938 found 1602177
parent transid verify failed on 22216704 wanted 1600938 found 1602177
parent transid verify failed on 22216704 wanted 1600938 found 1602177
Ignoring transid failure
parent transid verify failed on 13577821667328 wanted 1602089 found 1602242
parent transid verify failed on 13577821667328 wanted 1602089 found 1602242
parent transid verify failed on 13577821667328 wanted 1602089 found 1602242
Ignoring transid failure
leaf parent key incorrect 13577821667328
WARNING: could not setup extent tree, skipping it
parent transid verify failed on 13577821667328 wanted 1602089 found 1602242
Ignoring transid failure
leaf parent key incorrect 13577821667328
Couldn't setup device tree
ERROR: cannot open file system

gargamel:~# btrfs --version
btrfs-progs v5.10.1 

Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
 
Home page: http://marc.merlins.org/                       | PGP 7F55D5F27AAF9D08