How to Start, Stop and Enable Services on Linux with systemctl
A web server, a database, SSH, Docker — the useful things on a server all run as services: programs that start at boot and keep running in the background. systemctl is the remote control for them. Learn five subcommands and you can manage anything.
Quick reference
| Task | Command |
|---|---|
| Is it running? | systemctl status nginx |
| Start / stop / restart | sudo systemctl start nginx (or stop, restart) |
| Reload config without a restart | sudo systemctl reload nginx |
| Start at boot | sudo systemctl enable nginx |
| Don't start at boot | sudo systemctl disable nginx |
| Enable and start now | sudo systemctl enable --now nginx |
| List everything that's failed | systemctl --failed |
1. Check a service
systemctl status ssh
The important line is Active: — active (running) is good, inactive (dead) means it's stopped, failed means it crashed. The last few log lines are shown underneath, which is usually enough to see why. Press q to get out.
2. Start, stop, restart
sudo systemctl start nginx
sudo systemctl stop nginx
sudo systemctl restart nginx
restart stops and starts. Some services support reload, which re-reads the config without dropping connections — use it for Nginx after editing a site file.
3. Enable and disable
Starting a service only lasts until the next reboot. To make it start automatically every time:
sudo systemctl enable nginx
disable undoes it. enable --now enables and starts in one go — you'll see it in almost every install guide.
Note that enabled and running are separate: a service can be running now but not enabled (it won't survive a reboot), or enabled but stopped.
4. What's running?
systemctl list-units --type=service
systemctl --failed
The second one is the first thing to run when "something's not working" — it lists services that have crashed.
5. Logs for a service
journalctl -u nginx -n 50
journalctl -u nginx -f
-n 50 shows the last 50 lines; -f follows new ones. More on logs in the next tutorial.
Run your own script as a service
Say you have a script at /home/john/bot.py that should run all the time. Create a service file:
sudo nano /etc/systemd/system/bot.service
[Unit]
Description=My bot
After=network.target
[Service]
User=john
WorkingDirectory=/home/john
ExecStart=/usr/bin/python3 /home/john/bot.py
Restart=on-failure
[Install]
WantedBy=multi-user.target
Then:
sudo systemctl daemon-reload
sudo systemctl enable --now bot
Restart=on-failure restarts it if it crashes. daemon-reload is needed whenever you create or edit a service file.
Troubleshooting
"Unit nginx.service not found." It isn't installed, or the name is different. systemctl list-unit-files | grep -i name to find it.
Status says "failed". Run journalctl -u name -n 50 for the reason — usually a config typo or a port already in use.
Changes to a service file do nothing. You forgot sudo systemctl daemon-reload.
It runs when you start it but not after reboot. You started it but didn't enable it.
Wrapping up
status to look, start/stop/restart to control, enable to survive reboots, --failed to find trouble, and journalctl -u to read why. Everything that runs in the background on your server answers to those commands.
