After upgrading the host from Ubuntu 20.04 to 22.04, all Ubuntu 16.04 containers don’t boot properly. They start, but only have the /sbin/init processes running, nothing else:
# ps auxf
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 21 0.2 0.0 51612 3144 pts/1 Ss 20:30 0:00 su -l
root 22 0.6 0.0 21424 3992 pts/1 S 20:30 0:00 \_ -su
root 70 0.0 0.0 37368 3296 pts/1 R+ 20:31 0:00 \_ ps auxf
root 1 0.0 0.0 36436 1864 ? Ss 20:29 0:00 /sbin/init
#
Not sure how to debug this.