Package: systemd
Version: 252.12-1
Since Debian Bookworm (systemd 252), the reboot, poweroff and "shutdown
now" commands throw the following error if the dbus service is not running:
-------
Failed to connect to bus: No such file or directory
-------
and if dbus is running, but systemd-logind is not:
-------
Failed to set wall message, ignoring: Unit
dbus-org.freedesktop.login1.service failed to load properly, please
adjust/correct and reload service manager: File exists
Call to Reboot failed: Unit dbus-org.freedesktop.login1.service failed
to load properly, please adjust/correct and reload service manager: File
exists
-------
The action however finishes properly. I know that systemd-logind is
required for scheduled shutdowns/reboots, but it is not for immediate
ones. I am not sure if those were ever supposed to send a wall message,
as the possible purpose is minimal if the action is performed
immediately. However, the "wall" command works perfectly fine without
the two services and until Debian Bullseye, those errors were not thrown.
The "--no-wall" flag, which is supposed to suppress wall messages sent
by those commands, has no effect on the dbus/systemd-logind contact
attempt/error messages. Also I could not find any setting in
/etc/systemd to change this new behaviour. "reboot -f" works, but it has
unwanted implications, most notably no "sync" and unclean/no umounts.
The motivation to solve these errors without installing dbus and
enabling systemd-logind is that both are not required on most server
systems. systemd-logind is used for desktop sessions and by some GUI
applications, and for mentioned scheduled shutdowns/reboots, but for a
single admin server system it is usually not needed/used. For embedded
systems with low power/RAM it can hence make sense to have
systemd-logind masked and dbus uninstalled, to free up some resources,
cleanup the process tree, logs etc.
I guess it is an upstream question/issue, but I wanted to be sure about
this first. Hopefully someone can give more insights.
Best regards,
Micha
