[PROBLEM] Xbian doesn't boot

[Nachteule]

Ok, you can enter into rescue mode, thats good.

Unfortunately you can not do so much there, but what you could do is

1) run rch to chroot into your normal system. so, you can check if your home is mounted (it should)
2) you can mount root fs as follows and enter into root subvol folder:

Terminal

'reb' to unmount all filesystems, sync writes and reboot
'rum' to unmount all filesystems
'rch' to chroot into your XBian installation in /rootfs

/ # mount /dev/root /mnt
/ # cd /mnt
/mnt # cd root
/mnt/root # ls -la
total 16
drwxr-xr-x 1 root root 348 May 18 10:41 .
drwxr-xr-x 1 root root 52 Apr 14 11:43 ..
drwxr-xr-x 1 root root 560 May 16 11:12 @
drwxr-xr-x 1 root root 560 May 16 11:12 @btrfs-auto-snap_apt-run-2020-05-17-2323
drwxr-xr-x 1 root root 560 May 16 11:12 @btrfs-auto-snap_daily-2020-05-18-1240
drwxr-xr-x 1 root root 560 Apr 25 18:28 @btrfs-auto-snap_monthly-2020-04-26-2014
drwxr-xr-x 1 root root 560 May 16 11:12 @btrfs-auto-snsnapap_weekly-2020-05-18-1241
drwxr-xr-x 1 root root 560 May 16 11:12 @last_good_known
/mnt/root #

Then you could try to activate older snapshot (hopefully you have them) by

Terminal

mv @ @-bad
mv @btrfs-auto-snsnapap_weekly-2020-05-18-1241 @
sync
reb

Those commands moves away broken root subvol (@), activates a weekly done snapshot (@btrfs-auto-snsnapap_weekly-2020-05-18-1241), stores everything on disk and reboots

Of course you can do the same with home subvol, just cd home instead of cd root

and last but not least

3) you can test the network by issuing commands described in the intro text