Re: BTRFS - Error After Power Outage

[Roman Mamedov <rm@romanrm.net>]

On Wed, 25 Aug 2021 14:50:18 -0700
Evan Zimmerman <wolfblitz98@gmail.com> wrote:

> Hello!
> 
> I have a multi device btrfs array of 6 devices that is timing out or
> otherwise failing to mount on boot causing me to enter recovery mode,
> though I can manually mount the drives in recovery mode and can still
> see my data.
> 
> I was working in my house the other day, when our power had gone out.
> I turned my Debian server back on and it started up in emergency mode
> saying BTRFS error: open_ctree failed. I also got a "failed to mount
> /mnt/data", which is where I have my data.
> 
> Now, I've had a similar problem before where I believe one of my
> EasyStore drives was taking too long to be read from and causing
> Debian to boot into emergency mode, but after restarting it a few
> times, it would manage to finally boot up. This "fix" is not working
> this time around and I fear something corrupted during that power
> outage.
> 
> I'm hoping to get some advice on this to see what I can do to get
> things up and running again. Now, trying to mount manually actually
> worked in emergency mode. Thank you in advance for any help you all
> can provide!
> 
> # uname -a
> Linux [server_name] 5.9.0-5-amd64 #1 SMP Debian 5.9.15-1 (2020-12-17)
> x86_64 GNU/Linux
> 
> # btrfs --version
> btrfs-progs v5.9
> 
> # btrfs fi show
> Label: 'Media'  uuid: c29b9859-ae32-4be2-ad28-9193c9ebcc87
> Total devices 6 FS bytes used 28.24TiB
> devid    1 size 10.91TiB used 9.80TiB path /dev/sdd
> devid    2 size 2.73TiB used 2.68TiB path /dev/sdc
> devid    3 size 3.64TiB used 3.58TiB path /dev/sdb
> devid    4 size 2.73TiB used 2.67TiB path /dev/sde
> devid    5 size 2.73TiB used 1.61TiB path /dev/sdf
> devid    6 size 9.10TiB used 7.98TiB path /dev/sdg
> 
> # dmesg | grep btrfs

Are you sure it's the actual and complete output of the command?
"grep btrfs" without -i would not have returned any of those lines.
And most importantly it looks as if a few might be missing, better just post
the entire dmesg.

> [   16.106923] BTRFS: device label Media devid 6 transid 3072649
> /dev/sdg scanned by systemd-udevd (301)
> [   16.492767] BTRFS info (device sdd): setting incompat feature flag
> for COMPRESS_ZSTD (0x10)
> [   16.492768] BTRFS info (device sdd): force zstd compression, level 2
> [   16.492768] BTRFS info (device sdd): using free space tree
> [   16.492769] BTRFS info (device sdd): has skinny extents
> [  114.864229] BTRFS error (device sdd): open_ctree failed


-- 
With respect,
Roman