systemd unit indirect status

Question

I wonder how can I check which unit activates another with status indirect?

I run Arch with Gnome and a Debian server. On my Debian machine I can see that output for systemctl list-unit-files --type=target --state=enabled shows, as expected:

default.target    enabled
multi-user.target enabled

But on Arch desktop, surprisingly for me, it doesn't, although both: multi-user.target and graphical.target (my default on arch) are active. When I check the status of these units files they are both: indirect. When I list-dependencies for graphical.target it shows gdm.service and multi-user.target. In gdm unit file I do not see Also= in [Install] section. So what exactly activates graphical.target?

What is the reason of this "indirect" solution?

Answer 1

From man systemd.special:

graphical.target

       A special target unit for setting up a graphical login screen.
       This pulls in multi-user.target.

       Units that are needed for graphical logins shall add Wants= dependencies for their unit to this unit (or multi-user.target) during installation.
       This is best configured via WantedBy=graphical.target in the unit's [Install] section.

So the contents of your gdm.service would explain things more...

---

Below are the info of those two service on my system, take note of them being "static"...

$ systemctl status multi-user.target graphical.target

● multi-user.target - Multi-User System
     Loaded: loaded (/lib/systemd/system/multi-user.target; static)
     Active: active since Mon 2023-09-04 09:34:27 +03; 11h ago
      Until: Mon 2023-09-04 09:34:27 +03; 11h ago
       Docs: man:systemd.special(7)

Sep 04 09:34:27 kubuntu systemd[1]: Reached target multi-user.target - Multi-User System.

● graphical.target - Graphical Interface
     Loaded: loaded (/lib/systemd/system/graphical.target; static)
     Active: active since Mon 2023-09-04 09:34:27 +03; 11h ago
      Until: Mon 2023-09-04 09:34:27 +03; 11h ago
       Docs: man:systemd.special(7)

Sep 04 09:34:27 kubuntu systemd[1]: Reached target graphical.target - Graphical Interface.

$ systemctl cat multi-user.target graphical.target

# /lib/systemd/system/multi-user.target
#  SPDX-License-Identifier: LGPL-2.1-or-later
#
#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

[Unit]
Description=Multi-User System
Documentation=man:systemd.special(7)
Requires=basic.target
Conflicts=rescue.service rescue.target
After=basic.target rescue.service rescue.target
AllowIsolate=yes

# /lib/systemd/system/graphical.target
#  SPDX-License-Identifier: LGPL-2.1-or-later
#
#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

[Unit]
Description=Graphical Interface
Documentation=man:systemd.special(7)
Requires=multi-user.target
Wants=display-manager.service
Conflicts=rescue.service rescue.target
After=multi-user.target rescue.service rescue.target display-manager.service
AllowIsolate=yes

$ ls -la /lib/systemd/system/{multi-user,graphical}.target
-rw-r--r-- 1 root root 606 Jan 26  2023 /lib/systemd/system/graphical.target
-rw-r--r-- 1 root root 540 Jan 26  2023 /lib/systemd/system/multi-user.target