btrfs sits on md RAID-5:
/dev/md2 /data btrfs noatime,compress-force=zstd,space_cache=v2,noauto 0
0
After upgrading from kernel 4.16.1 to 4.19.1 and a clean restart, the fs
no longer mounts:
# mount /data
mount: wrong fs type, bad option, bad superblock on /dev/md2,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so.
# dmesg
[ 322.877321] BTRFS info (device md2): force zstd compression, level 0
[ 322.877326] BTRFS info (device md2): enabling free space tree
[ 322.877329] BTRFS info (device md2): using free space tree
[ 322.877330] BTRFS info (device md2): has skinny extents
[ 367.832058] BTRFS error (device md2): bad tree block start, want
21120019922944 have 620757027
[ 367.832116] BTRFS error (device md2): failed to read block groups: -5
[ 367.891339] BTRFS error (device md2): open_ctree failed
The error (bad tree block start) in dmesg changes every time as I re-run
"mount /data":
[ 589.425362] BTRFS error (device md2): bad tree block start, want
22008094932992 have 3378573292323635748
[ 589.425423] BTRFS error (device md2): failed to read block groups: -5
[ 589.469979] BTRFS error (device md2): open_ctree failed
[ 680.585908] BTRFS error (device md2): bad tree block start, want
21058406105088 have 18446616720224032488
[ 680.585991] BTRFS error (device md2): failed to read block groups: -5
[ 680.625419] BTRFS error (device md2): open_ctree failed
Any advice how to recover?
Tomasz Chmielewski
https://lxadm.com
