Systemd

This section contains a few one liners to help with everyday systemd operations

systemctl

Enable a service (making it start at boot time)

$ systemctl enable nginx.service

Disable a service

$ systemctl disable nginx.service

Start a service

$ systemctl start nginx.service

Stop a service

$ systemctl stop nginx.service

Restart a service

$ systemctl restart nginx.service

Reload a service

$ systemctl reload nginx.service

Status of a service

$ systemctl status nginx.service

List all of the units that systemd has loaded or attempted to load into memory

$ systemctl list-units --all # --list-unit-files list everything

Make journald persistent

$ mkdir -p /var/log/journal

$ cat /etc/systemd/journald.conf

[...]
[Journal]
Storage=persistent # set Storage to persistent

Display the timestamps in UTC

$ journalctl --utc

View log since last boot

$ journalctl -b

View log since a specified date

$ journalctl --since "2018-09-10 20:00" # --until can be used too

Follow logs (à la tail -f)

$ journalctl -f

Check a service log

$ journalctl -u crond

Check entries that involve an executable

$ journalctl /usr/bin/bash