Systemd
Quick reference for managing services and the system state on Engicam boards running systemd-based Linux distributions.
Service Management
| Command |
Description |
systemctl start <service> |
Start a service |
systemctl stop <service> |
Stop a running service |
systemctl restart <service> |
Restart a service |
systemctl reload <service> |
Reload configuration without restarting |
systemctl enable <service> |
Enable service to start on boot |
systemctl disable <service> |
Disable service from starting on boot |
systemctl status <service> |
Show current status and recent logs |
systemctl show <service> |
Show all properties of a service |
| Command |
Description |
systemctl list-units |
Show all loaded units and their state |
systemctl list-unit-files |
Show unit files and enabled/disabled state |
systemctl list-dependencies <unit> |
Show unit dependency tree |
systemctl list-jobs |
Show active systemd jobs |
systemctl get-default |
Show default boot target |
System State
| Command |
Description |
systemctl reboot |
Reboot the system |
systemctl poweroff |
Power off the system |
systemctl emergency |
Drop to emergency shell |
systemctl default |
Return to default target |
Logs with journald
| Command |
Description |
journalctl |
Show all collected log messages |
journalctl -u <service> |
Show logs for a specific service |
journalctl -f |
Follow logs in real time |
journalctl -k |
Show kernel messages only |
journalctl --since "10 min ago" |
Show recent entries |
Writing a Custom Service
Create a unit file at /etc/systemd/system/<name>.service:
[Unit]
Description=My Custom Service
After=network.target
[Service]
Type=simple
ExecStart=/usr/bin/my-app
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
Then enable and start it:
systemctl daemon-reload
systemctl enable my-custom.service
systemctl start my-custom.service