systemctl command

`systemctl` - Control the systemd system and service manager

The systemctl command in Linux is the primary tool for managing services, units, and the system state on systems using systemd, the modern init system found in most current Linux distributions (e.g., Ubuntu, Debian, Fedora, CentOS). It allows you to start, stop, restart, enable, disable, and inspect services and other system components.

Usage: systemctl [OPTIONS...] COMMAND [UNIT...]

COMMAND: The action to perform (e.g., start, stop, status).
UNIT: The target of the action (e.g., ssh.service, network.target).
OPTIONS: Flags that modify behavior (less common).

Common Commands

Command	Description
`start`	Start a service
`stop`	Stop a service
`restart`	Restart a service
`reload`	Reload configuration
`status`	Check service status
`enable`	Enable service at boot
`disable`	Disable service at boot
`is-active`	Check if running (returns `active` or `inactive`)
`is-enabled`	Check if enabled at boot

Examples

Basic Service Management

Control services like web servers, SSH, or databases with these core commands.

Start a Service:
```
sudo systemctl start ssh.service
```
- Starts the SSH service (often sshd.service on some systems).
Stop a Service:
```
sudo systemctl stop ssh.service
```
- Stops the SSH service.
Restart a Service:
```
sudo systemctl restart ssh.service
```
- Stops and then starts the service.
Reload a Service:
```
sudo systemctl reload ssh.service
```
- Reloads configuration without interrupting the service (if supported).
Check Status:
```
systemctl status ssh.service
```
- Output (example):
```
● ssh.service - OpenBSD Secure Shell server
  Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled)
  Active: active (running) since Tue 2025-04-01 10:00:00 UTC; 1h ago
  Main PID: 1234 (sshd)
```
- Shows if it’s running, PID, and recent logs.
Note: .service is optional—systemctl status ssh works too.
Enabling and Disabling Services

Control whether a service starts automatically at boot.

Enable a Service:
```
sudo systemctl enable ssh.service
```
- Sets the service to start on boot.
Disable a Service:
```
sudo systemctl disable ssh.service
```
- Prevents the service from starting on boot.
Check Enabled Status:
```
systemctl is-enabled ssh.service
```
- Output: enabled or disabled.
Listing Units

See what’s running or available on your system.

List Active Services:
```
systemctl list-units --type=service
```
- Shows all active services (e.g., ssh.service, nginx.service).
List All Services:
```
systemctl list-units --type=service --all
```
- Includes stopped services.
List Unit Files:
```
systemctl list-unit-files --type=service
```
- Shows all service files and their enabled/disabled state (e.g., enabled, disabled, static).
System-Level Commands

Manage the entire system with systemctl.

Reboot:
```
sudo systemctl reboot
```
Power Off:
```
sudo systemctl poweroff
```
Suspend:
```
sudo systemctl suspend
```
Viewing Logs

Pair systemctl with journalctl for detailed logs.

Service Logs:
```
journalctl -u ssh.service
```
- Shows logs for the SSH service.
Recent Logs:
```
journalctl -u ssh.service -n 10
```
- Last 10 lines of logs.

To get help related to the systemctl command use --help option

For more details, check the manual with man systemctl

systemctl - Control the systemd system and service manager​

Examples​

`systemctl` - Control the systemd system and service manager

Examples