LXD container processes hanging and commands not working

Hi guys!

On one of my servers I’ve observed an issue with LXD service twice. The processes get hung up for some reason inside the container and then if I try reboot from within the container or stop/start from server, the container just hangs.

LXC stop command is hung up for a while with no response on the terminal… I ended up rebooting the server to resolve this but I need a solution to resolve this permanently. Kindly help.

Server configuration:
OS: Ubuntu 18.04
LXD version: 4.21 (installed with snap)

Update:
I ran the following command to see the logs:
sudo cat /var/snap/lxd/common/lxd/logs/lxd.log

Observed this error log:

t=2022-01-05T17:21:21+0000 lvl=eror msg=“Error calling 'lxd forknet” err=“Failed to run: /snap/lxd/current/bin/lxd forknet info – 3865 -1: Failed setns to container network namespace: No such file or directory” instance=q457c0cc5109a instanceType=container pid=3865 project=default

Any suggestions on what this error message indicates?

Lxc container show log info gave the following information:
lxc info --show-log 457c0cc5109a

Name: q457c0cc5109a
Status: RUNNING
Type: container
Architecture: x86_64
PID: 3865
Created: 2021/12/14 07:23 UTC
Last Used: 2022/01/05 05:44 UTC

Resources:
Processes: 20
CPU usage:
CPU usage (in seconds): 131261
Memory usage:
Memory (current): 35.57GiB
Memory (peak): 63.33GiB

Log:

lxc q457c0cc5109a 20220105054408.345 ERROR utils - utils.c:lxc_can_use_pidfd:1774 - Kernel does not support pidfds
lxc q457c0cc5109a 20220105054408.409 ERROR conf - conf.c:turn_into_dependent_mounts:3906 - No such file or directory - Failed to recursively turn old root mount tree into dependent mount. Continuing…