Re: Unable to mount, even in recovery, parent transid verify failed on raid 1

[Nikolay Borisov <nborisov@suse.com>]

On 20.08.19 г. 21:17 ч., David Radford wrote:
> I have two 2TB spinning disks with full disk btrfs in raid 1. I am
> unable to mount the disks using any method I have found online. I've
> attached what I hope are the relevant logs. I had to edit them down to
> meet the file size limit.
> 
> uname: Linux babylon 5.2.9-arch1-1-custom-btrfs #1 SMP PREEMPT Mon Aug
> 19 06:41:35 PDT 2019 x86_64 GNU/Linux (Standard Arch Linux kernel
> compiled with Qu's new rescue patch
> https://patchwork.kernel.org/project/linux-btrfs/list/?series=130637)

SO what event predates this inability to mount? Did you experience any
hard resets - system hangs etc that prompted you to reboot your machine?
Have you changed your kernel recently ? There really isn't much to go on
in here? At the very least DO NOT run any of the repair functionality in
btrfs-progs just yet.

> 
> btrfs-progs v5.2.1
> 
> [root@babylon ~]# btrfs fi show
> Label: 'linux'  uuid: 3fd368de-157c-4512-8985-2be93a21a371
>     Total devices 1 FS bytes used 102.48GiB
>     devid    1 size 119.24GiB used 110.31GiB path /dev/sdb1
> 
> Label: none  uuid: 2507581c-dec0-4fdd-afe7-1f7c7ff66c6d (this is the
> one unountable)
>     Total devices 2 FS bytes used 1.54TiB
>     devid    1 size 1.82TiB used 790.03GiB path /dev/sdc
>     devid    2 size 1.82TiB used 790.03GiB path /dev/sdd
> 
> mounting with usebackuproot and rescue=skip_bg results in
> [ 1088.130629] BTRFS info (device sdc): trying to use backup root at mount time
> [ 1088.130633] BTRFS info (device sdc): disk space caching is enabled
> [ 1088.130635] BTRFS info (device sdc): has skinny extents
> [ 1088.135907] BTRFS error (device sdc): parent transid verify failed
> on 30425088 wanted 18663 found 18664
> [ 1088.151587] BTRFS error (device sdc): parent transid verify failed
> on 30425088 wanted 18663 found 18664
> [ 1088.151605] BTRFS warning (device sdc): failed to read root (objectid=2): -5
> [ 1088.151902] BTRFS error (device sdc): parent transid verify failed
> on 30425088 wanted 18663 found 18664
> [ 1088.152134] BTRFS error (device sdc): parent transid verify failed
> on 30425088 wanted 18663 found 18664
> [ 1088.152143] BTRFS warning (device sdc): failed to read root (objectid=2): -5
> [ 1088.152519] BTRFS error (device sdc): parent transid verify failed
> on 30425088 wanted 18663 found 18664
> [ 1088.152633] BTRFS error (device sdc): parent transid verify failed
> on 30425088 wanted 18663 found 18664
> [ 1088.152640] BTRFS warning (device sdc): failed to read root (objectid=2): -5
> [ 1088.153462] BTRFS error (device sdc): parent transid verify failed
> on 343428399104 wanted 18163 found 19034
> [ 1088.153690] BTRFS error (device sdc): parent transid verify failed
> on 343428399104 wanted 18163 found 19034
> [ 1088.153699] BTRFS warning (device sdc): failed to read root (objectid=4): -5
> [ 1088.154714] BTRFS error (device sdc): parent transid verify failed
> on 343428399104 wanted 18163 found 19034
> [ 1088.154915] BTRFS error (device sdc): parent transid verify failed
> on 343428399104 wanted 18163 found 19034
> [ 1088.154921] BTRFS warning (device sdc): failed to read root (objectid=4): -5
> [ 1088.261675] BTRFS error (device sdc): open_ctree failed
> 
> btrfs-find-root log attached
> 
> I do have partial backup but it is a little outdated and would really
> appreciate help either fixing the filesystem, or finding out how to
> recover it with as minimal loss as possible. Thank you for the help!
>