SystemD

Booting, Shutting down and the like

Problems shutting down

In case there are problems:

RFE: when "systemctl poweroff" or "systemctl poweroff -f" fails, because PID 1 is hosed, recommend retrying with "systemctl poweroff -ff"

SystemD and tty

Don't clear tty1 before login screen appears

Debian 8: "edit" command of systemctl is not available.

systemctl edit getty@tty1

[Service]
TTYVTDisallocate=no

Credits

Set another number of ttys than 6

In /etc/systemd/logind.conf, locate NAutoVTs and change its value.

Credits

journald on tty

Let's have journald output on tty12 for example: Create file /etc/systemd/journald.conf.d/fw-tty12.conf (perform mkdir /etc/systemd/journald.conf.d/ if necessary) and put

[Journal]
ForwardToConsole=yes
TTYPath=/dev/tty12
MaxLevelConsole=info

inside this file, then do a

systemctl restart systemd-journald

Credits

Arbitrary program on specific tty

This SystemD service starts "htop" on tty11 (as user "nobody" for security reasons):

[Unit]
Description=htop on tty11

[Service]
Type=simple
ExecStart=/usr/bin/sudo -u nobody /usr/bin/htop
StandardInput=tty
StandardOutput=tty
TTYPath=/dev/tty11

[Install]
WantedBy=multi-user.target

It can be saved in /etc/systemd/system as htop.service and later be started by systemctl start htop. If it should be started at boot, systemctl enable htop can be used.

Credits - I have enhanced it by "sudo -u nobody", otherwise anybody with physical access to the system would be able to manipulate it, i.e. killing processes by pressing F9.

Networking

Accounting

Requires at least version 235 (Debian 11 has 247, Ubuntu 20.04 LTS has 245).

In the service file, add this in section [[Service]]:

IPAccounting=yes

It can also be used for the time a program is running:

systemd-run -p IPAccounting=1 -t program

Tested on Ubuntu 20.04: Did not work!

Credits