Alex Ruben
How To Override and Configure Systemd Services on Linux and Ubuntu
If you’ve ever needed to tweak how stuff like nginx or other services behave on Linux, you probably ran into the mess of editing confusing config files or trying to patch things without breaking stuff. Using systemd override files is an actual lifesaver—keeps your changes clean, easy to undo, and way less risky than hacking the original configs directly. That way, if something goes sideways, just revert and you’re good to go. This can be especially handy if you’re managing a server or just want your local setup to behave a bit different from the default.
How to Fix / Override Systemd Services on Linux
Get into the terminal and back up your brain—then your configs
First thing: open your terminal (if you don’t already have it open). Usually Ctrl + Alt + T does the trick, or find it in your applications menu. Once there, it’s a good idea to check the current status of the service, so you know what you’re dealing with:
sudo systemctl status nginxThis is just to see the logs or errors if it’s acting up. Now, to change how nginx behaves without messing with its core files, you use systemctl edit. That command looks like:
sudo systemctl edit nginxThis opens a blank override file in your default editor—usually nano or vim—where you can put your custom settings. On one setup it might open nano, on another, vim. Don’t panic if you’re not super comfortable; just know that this is the safe zone for your tweaks.
Customizing service behavior — what to add and why
Inside that editor, add the settings you need. For example, to make nginx restart automatically if it crashes, you add:
[Service]
Restart=on-failureThis is helpful if nginx crashes unexpectedly but you don’t want to babysit it. The [Service] section is essential because it tells systemd you’re editing service-related settings. If you want to be more specific, you can even add other directives like LimitNOFILE=65535 or set environment variables.
Save, reload, and restart—the crucial quick steps
Once you’ve added your changes, save them. If you’re in nano, it’s Ctrl + O then Enter to save, then Ctrl + X to exit. After that, tell systemd to reload its new config with:
sudo systemctl daemon-reloadIt’s like saying, “Hey, systemd, look, I changed stuff.” Now, restart the service so your tweaks take effect:
sudo systemctl restart nginxIf everything’s correct, nginx should pick up your changes, and if it crashes or needs to restart, it’ll do so automatically thanks to that setting. Weird thing: sometimes, on certain setups, you might need to reboot or at least reload the whole systemd manager if things don’t seem to stick. Because of course, Linux has to make it harder than necessary.
Revert if needed—don’t set it and forget it
Ever change your mind? No sweat. To undo your override, just run:
sudo systemctl revert nginxThis will remove your custom override and let nginx run with its default config again. You can also just delete the override file manually in /etc/systemd/system/nginx.service.d/ if you’re feeling adventurous, but revert does the job neatly.
Extra tips & common hiccups
Some gotchas I’ve run into:
- Always back up your configs—because Linux has to make it more complicated than it needs to be.
- If nginx isn’t behaving like you expect, run
sudo systemctl status nginxorjournalctl -u nginxand see what’s up. - If your changes don’t seem to take, try running
sudo systemctl daemon-reexecor a full reboot. Yeah, it’s annoying but sometimes necessary.
And just a side note—can’t hurt to double-check if your override files are in the right spot: /etc/systemd/system/nginx.service.d/ or similar. If you manually messed with the main *.service file, that’s bad news—override files should be the way to go.
Wrap-up
This method keeps things tidy and safe while letting you tweaked systemd services to behave just how you want. It’s pretty straightforward, but a little fiddly if you’re new at it—just takes patience and paying attention to where your configs go. When used right, it’s a more elegant way to control services without breaking your system or losing your changes after updates.
Summary
- Use sudo systemctl edit <service> to create override files
- Add custom options under [Service]
- Save, reload with sudo systemctl daemon-reload
- Restart the service to test
- Revert changes with sudo systemctl revert <service> when needed
Fingers crossed this helps
Hopefully, this shaves off a few hours or at least stops you from going totally nuts trying to tweak services without breaking everything. It’s a solid technique once you get the hang of it, and it’s way better than editing system files directly. Just remember, Linux is weird sometimes, but patience pays off.