systemd

Link

https://systemd.io/

Linux init system (base system component)

Resources

• Service unit configuration
• Timers
• systemd user services
• systemd by example

  The playground allows you to learn about systemd interactively, right from your browser! Create examples without the danger of breaking your system, and without being distracted by hundreds of unrelated unit files.

• Rethinking PID 1 - systemd announcement

journald

• Introduction to the Systemd journal

nspawn

• ArchWiki
• Debian Wiki
• Fedora Magazine (❗ dated article written 2016-06-28)
• Jip-Hop/jailmaker - persistent Linux ‘jails’ on TrueNAS to install software (k3s, docker, portainer, podman, etc.) with full access to all files via bind mounts thanks to systemd-nspawn

FAQ

List enabled timers and their next run date

systemctl list-timers

Which user services are running?

To find out which systemd user units are running, you can use the following command:

systemctl --user list-units --type=service --state=running

Explanation of the command:

• --user: Checks the user-specific systemd instance.
• list-units: Lists the currently active units.
• --type=service: Filters the output to only include services. You can omit this or replace it with another type (e.g., --type=socket).
• --state=running: Limits the output to only the running units.