Hi there, I believe I am having the same issue, but I am very rusty as I am stepping back into Linux after a long break…
I have just booted up a Linux box after it was dormant for about a year. After updating to 20.04, I am having a ton of graphical issues and it seems that LXD has been messed up a bit.
sudo apt --fix-broken install
Preconfiguring packages …
(Reading database … 538488 files and directories currently
Preparing to unpack …/archives/lxd_1%3a0.7_all.deb …
Warning: Stopping lxd.service, but it can still be activated
=> Installing the LXD snap
==> Checking connectivity with the snap store
==> Installing the LXD snap from the latest track for ubuntu-
snap “lxd” is already installed, see ‘snap help
==> Waiting for LXD to be online (10min timeout)
==> Running migration from Deb to Snap
=> Connecting to source server
=> Connecting to destination server
=> Running sanity checks
error: Target LXD already has containers, aborting.
dpkg: error processing archive /var/cache/apt/archives/lxd_1%
new lxd package pre-installation script subprocess returned
> error exit status 1
> Job for lxd-containers.service failed because the control pro
> cess exited with error code.
> See “systemctl status lxd-containers.service” and "journalctl
> -xe" for details.
> Errors were encountered while processing:
> E: Sub-process /usr/bin/dpkg returned an error code (1)
Client version: 4.3
Server version: 4.3
If I run > systemctl status lxd-containers.service
lxd-containers.service - LXD - container startup/shutdown
Loaded: loaded (/lib/systemd/system/lxd-containers.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Sun 2020-07-12 21:59:58 PDT; 10min ago
Main PID: 19134 (code=exited, status=1/FAILURE)
Jul 12 21:59:58 czar systemd: Starting LXD - container startup/shutdown…
Jul 12 21:59:58 czar lxd: Error: User “root” has no subuids
Jul 12 21:59:58 czar systemd: lxd-containers.service: Main process exited, code=exited, status=1/FAILURE
Jul 12 21:59:58 czar systemd: lxd-containers.service: Failed with result ‘exit-code’.
Jul 12 21:59:58 czar systemd: Failed to start LXD - container startup/shutdown.
I believe it is similar to the above, but I do not know what exactly to add to the fstab to update the necessary links. Any help on this would be great. 18.04 was working great, now I am stuck in 4:3 resolution.
Please let me know if I am missing any necessary information.