LXD unix socket not accessible:

I am running LXD 5.21.1 LTS on top of ubuntu 20.4. via snap and could not access anything any longer

symptom:

sysop@ubn2004LXD:~$ lxc list
Error: LXD unix socket not accessible: Get "http://unix.socket/1.0": EOF

checking the daemon

sysop@ubn2004LXD:~$ sudo systemctl status snap.lxd.daemon
...
...
Jun 20 23:12:41 ubn2004LXD lxd.daemon[24852]: time="2024-06-20T23:12:41+02:00" level=warning msg=" - Couldn't find the CGroup blkio.weight, disk priority will be ignored"
Jun 20 23:12:41 ubn2004LXD lxd.daemon[24852]: time="2024-06-20T23:12:41+02:00" level=warning msg=" - Couldn't find the CGroup memory swap accounting, swap limits will be ignored"
Jun 20 23:12:41 ubn2004LXD lxd.daemon[24852]: time="2024-06-20T23:12:41+02:00" level=warning msg="Instance type not operational" driver=qemu err="KVM support is missing (no /dev/kvm)" type=>
Jun 20 23:12:43 ubn2004LXD lxd.daemon[24852]: time="2024-06-20T23:12:43+02:00" level=error msg="Failed loading storage pool" err="Required tool 'zpool' is missing" pool=pool-52G
Jun 20 23:12:43 ubn2004LXD lxd.daemon[24852]: time="2024-06-20T23:12:43+02:00" level=error msg="Failed to start the daemon" err="Failed applying patch \"storage_move_custom_iso_block_volume>

now, the zpool error lead me to:
LXD 5.12: ZFS stopped working in lxd - Error: Required tool 'zpool' is missing when kernel ZFS module version < 0.8:
however I am not using zfs but btrfs, so the metioned pool-52G is a btrfs powerd pool

what worries me a bit is:

sysop@ubn2004LXD:~$ sudo ls -l /var/snap/lxd/common/lxd/storage-pools/pool-52G/containers/erpnext4
total 0

or

sysop@ubn2004LXD:~$ sudo du -h -d 1 /var/snap/lxd/common/lxd/storage-pools/pool-52G/containers
4.0K	/var/snap/lxd/common/lxd/storage-pools/pool-52G/containers/ubn2204
4.0K	/var/snap/lxd/common/lxd/storage-pools/pool-52G/containers/erpnext4
12K	/var/snap/lxd/common/lxd/storage-pools/pool-52G/containers

any idea how to proceed from here?

I would ask this question at LXD discourse forum, because this is an Incus forum. Incus is a LXD fork created when Canonical took over the project.

such a “Not responsible” kind of answer is the most unexpected thing I to happen and does not match my experience in here at all during my ~7 years of membership.

  1. I have experienced a pretty similar disappearance of content of btrfs backed /var/lib/incus/storage-pools/pool1/...
  2. There are still quite some recent Topics under the lxd flag in here which seem to be discussed & solved as usual
  3. When I created that LXD host noone even knew what things might happen to the project & I am on the incus side of things for everything coming in the future

That said … I am still hoping for anybody to come to the rescue in some way or another.

The issue you’re running into is specific to LXD and looks like a snap related issue, so it’s definitely correct to send folks to LXD support.