Managing System Services in Linux | systemctl Command
Last Updated :
13 Nov, 2025
Systemd is a modern system and service manager for Linux that serves as the core initialization process (PID 1). It controls system startup, manages background services, and ensures efficient system operation.
- Starts automatically as the first process when the Linux kernel boots.
- Manages all other processes during system runtime.
- Uses parallelization to launch multiple services simultaneously, speeding up boot time.
- Organizes system components into “units” such as services, sockets, devices, mounts, and timers.
- Controlled via the systemctl command-line tool (start, stop, enable, disable, and check services).
Example: Starting and Stopping a System Service in Linux:
Syntax:
systemctl start [service_name]
systemctl stop [service_name]
systemctl status [service_name]
Example with Apache Web Server
Commands:
systemctl start apache2
systemctl status apache2
Output:
- The command systemctl start apache2 starts the Apache web server service.
- The command systemctl status apache2 displays the current status of the Apache service.
Command:
systemctl stop apache2
systemctl status apache2
Output:
- The command systemctl stop apache2 is used to stop the Apache web server.
- The command systemctl status apache2then checks whether the service is still running or stopped.
Syntax of `systemctl` command in Unix
systemctl [command] [service]
- [command] = The action we want to perform (start, stop, enable, disable, etc.)
- [service] = The name of the service we want to perform the action on.
Options available in `systemctl` command in Unix
| Option | Description | Example |
|---|
| --type | Filter output by unit type (service, socket, timer) | systemctl --type=service |
| --all | Lists all units including inactive ones | systemctl --all |
| --failed | Lists all units that have failed | systemctl --failed |
| --state | Filter output by unit state (active, inactive, failed) | systemctl list-units --state=failed |
| --user | Manage user services instead of system services | systemctl --user |
| -q, --quiet | Suppress output messages | systemctl daemon-reload --quiet |
Managing System Services in Linux
1. Enabling and Disabling Services
Enabling a Service
- Enables the Apache web server to start automatically at system boot.
Syntax:
systemctl enable [service]
Example:
sudo systemctl enable apache2
Output:
Disabling a Service
- Disables the Apache web server, preventing it from starting automatically at boot.
Syntax:
systemctl disable [service]
Example:
sudo systemctl disable apache2
Output:
2. Viewing the Status of a Service
- Displays the "current status" of Apache (whether it’s _active_, _inactive_, _running_, or _failed_).
Syntax:
systemctl status [service]
Example:
sudo systemctl status apache2
Output:
3. Restarting and Reloading Services
Restarting a Service
- Restarts the Apache web server, applying any configuration or update changes.
Syntax:
systemctl restart [service]
Example:
sudo systemctl restart apache2
Output:
Reloading a Service
- Reloads Apache configuration without completely stopping the service, useful after minor config edits.
Syntax:
systemctl reload [service]
Example:
sudo systemctl reload apache2
Output:
4. Masking and Unmasking Services
Masking a Service
- Prevents the Apache service from being started manually or automatically, even if required by other services.
Syntax:
systemctl mask [service]
Example:
sudo systemctl mask apache2
Output:
Unmasking a Service
- Allows the Apache service to be started or enabled again.
Syntax:
systemctl unmask [service]
Example:
sudo systemctl unmask apache2
Output:
5. Changing the Default Target
- Sets the system to boot into the graphical (GUI) mode by default instead of command-line mode.
Syntax:
systemctl set-default [target]
Example:
sudo systemctl set-default graphical.target
Output:
6. Listing Unit Files
- Lists all available unit files on the system, showing which are enabled, disabled, or static.
Syntax:
systemctl list-unit-files
Output:
7. Masking and Unmasking Unit Files
Masking a Unit File
- Prevents the Apache unit file from being started or enabled under any condition.
Syntax:
systemctl mask [unit-file]
Example:
sudo systemctl mask apache2.service
Output:
Unmasking a Unit File
- Restores the ability to start or enable the Apache unit file again.
Syntax:
systemctl unmask [unit-file]
Example:
sudo systemctl unmask apache2.service
Output:
Also Check:
Explore
Getting Started with Linux
Installation with Linux
Linux Commands
Linux File System
Linux Kernel
Linux Networking Tools
Linux Process
Linux Firewall
Shell Scripting & Bash Scripting
Linux Administrator System