systemd-logind

• loginctl

Jan 25 15:58:36 SERVER systemd-logind[876]: Failed to save user data /run/systemd/users/0: No space left on device

CoreOS

Sep 23 18:24:57 SERVER systemd-logind[916]: New session 5 of user XXXX 
See also: last

• systemd-logind: Power key pressed.
• systemd-logind: Powering Off...
• systemd-logind: System is powering down.

Ubuntu

Sep 27 07:29:04 SERVER systemd[1]: Stopping User Manager for UID 1001...
Sep 27 07:29:04 SERVER systemd[1]: Started Login Service.
Sep 27 07:29:04 SERVER systemd-logind[19487]: Watching system buttons on /dev/input/event1 (AT Translated Set 2 keyboard)
Sep 27 07:29:04 SERVER systemd-logind[19487]: Watching system buttons on /dev/input/event0 (Power Button)
Sep 27 07:29:04 SERVER systemd-logind[19487]: New seat seat0.
Sep 27 07:29:04 SERVER systemd[1]: Starting Login Service...
Sep 27 07:29:04 SERVER systemd[1]: Stopped Login Service.
Sep 27 07:29:04 SERVER systemd[1]: systemd-logind.service: Scheduled restart job, restart counter is at 1.
Sep 27 07:29:04 SERVER systemd[1]: systemd-logind.service: Service has no hold-off time, scheduling restart.
Sep 27 07:29:04 SERVER systemd[1]: systemd-logind.service: Failed with result 'watchdog'.
Sep 27 07:29:04 SERVER systemd[1]: systemd-logind.service: Main process exited, code=dumped, status=6/ABRT

See also

• systemd-logind
• Systemd: systemctl, systemd-journald, journalctl systemd-cat, systemd-logind, systemd-networkd:networkctl, systemd-timesyncd, systemd-resolved, systemd-udevd , Systemd-logind: loginctl, hostnamectl, udevadm, systemd-run, portablectl, systemd-nspawn, systemd resource management, Timer (systemd), systemd logs, /etc/systemd/, systemd services, systemd-mount, /run/systemd/, .service, /usr/lib/systemd/, /usr/lib/systemd/system/, /usr/lib/systemd/system/systemd-resolved.service, /lib/systemd/, machinectl, systemd-oomd, systemd-analyze

https://wiki.ubuntu.com/DebuggingSystemd