I woke up this morning and my system had crashed and my root filesystem was readonly. Reboot failed when mounting the root filesystem, and now my system will not boot. I had a USB I setup for recovery and booted into that and to help with recovery but I am currently stuck. Some background into. Root file system is RAID 1 with two 1TB drives (Both M.2 one is NVME and one is SATA) Original system is Ubuntu 18.04 with kernel 5.5.7 and btrfs-progs I think was version 5.6 I think last scrub on the pool was maybe 1-2 months ago. But sure exact timing. My recovery environment is ubuntu 20.04 with kernel 5.6.7 and btrfs-progs 5.6 and that is what I am running under at the moment When I try to mount the filesystem I get the following error. boot@boot-live-usb:~$ sudo mount /dev/sdm2 /media/root/ [sudo] password for boot: mount: /media/root: wrong fs type, bad option, bad superblock on /dev/sdm2, missing codepage or helper program, or other error. With dmesg showing [Mon May 11 08:56:47 2020] BTRFS info (device nvme0n1p2): disk space caching is enabled [Mon May 11 08:56:47 2020] BTRFS info (device nvme0n1p2): has skinny extents [Mon May 11 08:56:47 2020] BTRFS error (device nvme0n1p2): bad tree block start, want 2728265449472 have 5440864628575810330 [Mon May 11 08:56:47 2020] BTRFS error (device nvme0n1p2): bad tree block start, want 2728265449472 have 0 [Mon May 11 08:56:47 2020] BTRFS error (device nvme0n1p2): failed to read block groups: -5 [Mon May 11 08:56:47 2020] BTRFS error (device nvme0n1p2): open_ctree failed Trying a readonly check on the filesystem gave me the following error boot@boot-live-usb:~$ sudo btrfs check --readonly /dev/sdm2 Opening filesystem to check... checksum verify failed on 2728265449472 found 0000008B wanted 00000017 checksum verify failed on 2728265449472 found 000000B6 wanted 00000000 checksum verify failed on 2728265449472 found 0000008B wanted 00000017 bad tree block 2728265449472, bytenr mismatch, want=2728265449472, have=5440864628575810330 ERROR: failed to read block groups: Input/output error ERROR: cannot open file system I tried a restore (with -io options) to at least get as much data as I could off just to be safe and it finished but there was a number of checksum errors, bad tree block error and loop errors. So not sure how good the backup will be. Any help would be appreciated. I have backups so I could format and setup the system again, but would rather not if I don’t have too.
