After Lubuntu 18.04 installation, the system didn't boot, so I started root shell in recovery mode. I've observed that all systemd commands (e.g.
systemctl list-sockets) are very slow or time out. My attempts to debug this:
Looking at the output of
strace -p 1I've observed that systemd PID 1 is waiting in a ppoll(2) system call to receive data on the dbus socket, but that data never arrives.
ps ax | grep dbuscontains
919 ? Zs 0:0 [dbus-daemon] <defunct>, and the PID changes every few minutes.
systemctl list-jobsis very slow (or times out), it displays
1950 dbus.service start waiting.
journalctl -u dbus.service -b -fdispays a few instances of
Started D-Bus System Message Bus; 90 seconds later:
dbus.service: Main process exited, code=exited, status=1/FAILURE. It doesn't show any other messages (e.g. the error message by
I suspect that the root cause of
systemctl ... timeouts is that
dbus.service crashes shortly after it starts. How do I debug this further? Where can I see the logs (+ stdout + stderr) of
I'm new to systemd and dbus. I have some Linux debugging skills from the pre-systemd times.
journalctl -xeto see the systemd logs. But also you can manually start the dbus service to see what happens. The exact command-line arguments are in the
ExecStartoption of the
/lib/systemd/system/dbus.servicefile which is the actual service. For example mine is :
/usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation --syslog-only