systemd

https://twlinux.github.io/2017-10-24-sysadmin/

Systemd is the default init solution for many modern Linux distros. It manages daemons (background services).

daemon management

• systemd-analyze blame lists the services that started at boot, in descending order of time to initialize.
• systemctl start|stop UNIT activates (starts) or deactivates (stops) a unit immediately.
• systemctl enable|disable [--now] UNIT enables or disables services from starting at boot.
• systemctl status UNIT shows runtime status (active (running), inactive (dead), failed) and log messages of a unit.
• systemctl kill UNIT forces the service to end.
• systemctl restart UNIT restarts a unit.

journalctl queries the system logs, see man journalctl.