How to Start a Service in Linux: Simple Commands Explained

To start a service in Linux, use the systemctl start service-name command on modern systems with systemd. On older systems, you can use service service-name start. Replace service-name with the actual service you want to start.

Syntax

The basic syntax to start a service depends on your Linux system's init system.

• systemctl start <service-name>: Starts the service using systemd, the modern init system.
• service <service-name> start: Starts the service using the older SysV init system.

Replace <service-name> with the name of the service you want to start, like nginx or ssh.

bash

systemctl start <service-name>

service <service-name> start

Example

This example shows how to start the ssh service using systemctl. It demonstrates the command and the expected output when checking the service status.

bash

sudo systemctl start ssh
sudo systemctl status ssh --no-pager

Output

● ssh.service - OpenBSD Secure Shell server
   Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2024-06-07 10:00:00 UTC; 5s ago
 Main PID: 1234 (sshd)
    Tasks: 1 (limit: 4915)
   Memory: 2.0M
   CGroup: /system.slice/ssh.service
           └─1234 /usr/sbin/sshd -D

Common Pitfalls

Common mistakes when starting services include:

• Not using sudo or root privileges, which are required to start most services.
• Using the wrong command for your system's init system (e.g., using service on a system with systemd).
• Typos in the service name causing "Unit not found" errors.
• Trying to start a service that is disabled or not installed.

Always check the service name and your permissions before starting.

bash

sudo service ssh start  # Older systems
sudo systemctl start ssh  # Modern systems

Quick Reference

Command	Description
systemctl start	Start a service on systemd-based systems
service start	Start a service on SysV init systems
sudo systemctl status	Check the status of a service
sudo systemctl enable	Enable service to start on boot
sudo systemctl stop	Stop a running service

Key Takeaways

Use systemctl start service-name on modern Linux systems to start services.

Older Linux systems may require service service-name start instead.

Always run service start commands with sudo or as root.

Check the service name carefully to avoid errors.

Use systemctl status service-name to verify the service is running.