systemctl command: start, stop and inspect services

Syntax

systemctl subcommand service

It controls services, the programs that keep running in the background.

Try it first

Start by asking about the state.

$ systemctl status nginx
● nginx.service - A high performance web server and a reverse proxy server
   Loaded: loaded (/lib/systemd/system/nginx.service; disabled; vendor preset: enabled)
   Active: inactive (dead) since Mon 2026-03-23 08:00:00 UTC; 2h ago

Two lines are worth reading.

So it is stopped, and it will stay stopped after a reboot.

Starting it

Service operations need administrator rights.

$ systemctl restart nginx
Failed to restart nginx.service: Interactive authentication required.
See system logs and 'systemctl status nginx.service' for details.
$ sudo systemctl start nginx
$ systemctl status nginx
● nginx.service - A high performance web server and a reverse proxy server
   Loaded: loaded (/lib/systemd/system/nginx.service; disabled; vendor preset: enabled)
   Active: active (running) since Mon 2026-03-23 08:00:00 UTC; 2h ago
   Main PID: 1001 (nginx)
   Tasks: 2 (limit: 4915)
   Memory: 2.3M
   CGroup: /system.slice/nginx.service
           └─1001 /usr/sbin/nginx

Now active (running), with a process id. When you only want the state, is-active is shorter.

$ systemctl is-active nginx
active

Now, versus from the next boot

This is where systemctl catches people out. Starting it does nothing about the next boot.

$ systemctl is-enabled nginx
disabled

For a service that must survive a reboot, you need enable.

$ sudo systemctl enable nginx
Created symlink /etc/systemd/system/multi-user.target.wants/nginx.service → /lib/systemd/system/nginx.service.
$ systemctl is-enabled nginx
enabled

"It worked until we rebooted" is the sound of a missing enable.

Listing what is running

$ systemctl list-units --type=service
UNIT                                LOAD   ACTIVE   SUB     DESCRIPTION
nginx.service                       loaded active   running A high performance web server and a reverse proxy server
ssh.service                         loaded active   running OpenBSD Secure Shell server
cron.service                        loaded active   running Regular background program processing daemon
networking.service                  loaded active   running Raise network interfaces
systemd-resolved.service            loaded active   running Network Name Resolution

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

5 loaded units listed. Pass --all to see loaded but inactive units, too.

Only running units by default. Add --all to see the stopped ones too.

Stopping it

$ sudo systemctl stop nginx
$ systemctl is-active nginx
inactive

When you actually reach for it

systemctl is the first thing you type when something that should be running is not.

Read the state with status, read the reason with journalctl. Those two carry most of a server incident.

Things that trip people up

start and enable are not the same. With only start, the service is gone after the next reboot. When you want both, sudo systemctl enable --now nginx does them together.

.service can be left off. nginx and nginx.service mean the same thing. A name that does not exist says so.

$ systemctl status nosuchservice
Unit nosuchservice.service could not be found.

status is a summary. It will not tell you why a start failed. Read journalctl -u nginx for that.