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systemctl cheat sheet

Field-tested systemd commands for everyday admin work – searchable and copyable in one click. Units, timers, overrides and boot analysis.

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37 commands

Status & control

State and latest log lines of a unit
systemctl status nginx
Start a unit
sudo systemctl start nginx
Stop a unit
sudo systemctl stop nginx
Stop and start a unit again
sudo systemctl restart nginx
⚠ Careful: changes or deletes data
Reload the config without stopping
sudo systemctl reload nginx
Short state: active, inactive or failed
systemctl is-active nginx
Check whether the unit starts at boot
systemctl is-enabled nginx

Autostart & masking

Enable autostart at boot
sudo systemctl enable nginx
Enable autostart and start now
sudo systemctl enable --now nginx
Disable autostart
sudo systemctl disable nginx
Fully block a unit (also as dependency)
sudo systemctl mask nginx
⚠ Careful: changes or deletes data
Remove the mask
sudo systemctl unmask nginx
Re-read unit files after changes
sudo systemctl daemon-reload

Finding & inspecting units

List all failed units
systemctl --failed
List running services
systemctl list-units --type=service --state=running
Show the unit file including drop-ins
systemctl cat nginx
Dependency tree of a unit
systemctl list-dependencies nginx

Journal pointers

Follow the logs of a unit live
journalctl -u nginx -f
Messages from the last hour
journalctl -u nginx --since '1 hour ago'
Errors since the last boot
journalctl -b -p err
Disk space used by the journal
journalctl --disk-usage

Timers

All timers with next and last run
systemctl list-timers --all
Enable and start a timer
sudo systemctl enable --now backup.timer
Run the matching job once right now
sudo systemctl start backup.service
Timer line: every day at 03:00
OnCalendar=*-*-* 03:00:00
Timer line: catch up on missed runs after boot
Persistent=true
Validate a time expression and show next run
systemd-analyze calendar 'Mon *-*-* 06:00'

Overrides with drop-ins

Create a drop-in (survives package updates)
sudo systemctl edit nginx
Discard all local changes to the unit
sudo systemctl revert nginx
⚠ Careful: changes or deletes data
Drop-in [Service]: restart on failure (RestartSec=5 waits 5 s)
Restart=on-failure
Drop-in [Service]: cap memory at 1 GB
MemoryMax=1G
Drop-in [Service]: clear the inherited ExecStart before setting a new one
ExecStart=

Analysis & targets

Show total boot time
systemd-analyze
The 15 slowest units at boot
systemd-analyze blame | head -n 15
Sandboxing score of a unit
systemd-analyze security nginx
Boot without a graphical interface
sudo systemctl set-default multi-user.target
Switch to rescue mode (stops services)
sudo systemctl isolate rescue.target
⚠ Careful: changes or deletes data

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