jourtnalctl cheat sheet

journalctl man page:

Configuration

/etc/systemd/journald.conf

Show Service Log

journalctl --no-pager -u _service-name_

Show events since the last boot

journalctl -b

Show today events

journalctl --since=today

Show (follow) current events

journalctl -f

Control log size

Retain only the past two days:

journalctl --vacuum-time=2d

Retain only the past 500 MB:

journalctl --vacuum-size=500M