To manage Linux services effectively, use systemctl with systemd. 1. Start a service immediately with sudo systemctl start nginx.service. 2. Stop it with sudo systemctl stop nginx.service. 3. Restart using sudo systemctl restart nginx.service. 4. Reload configuration without restart via sudo systemctl reload nginx.service. 5. Enable at boot with sudo systemctl enable nginx.service or combine with start using enable --now. 6. Check status using systemctl status sshd.service. 7. List active services with systemctl list-units --type=service --state=active or all loaded services with --all. 8. View logs via sudo journalctl -u nginx.service, adding -f to follow in real time. For custom services, create a .service file in /etc/systemd/system/, then run sudo systemctl daemon-reload before enabling or starting. Troubleshoot failures by checking status and logs, ensuring correct file location and permissions, verifying executable paths, and adjusting service type for non-daemon scripts. Mastering these systemctl and journalctl commands provides a robust foundation for service management in production environments.

Managing Linux services effectively is a core skill for system administrators and developers working with modern Linux distributions. Most of today’s Linux systems use systemd as the init system — the first process that starts at boot and manages all other services. The primary tool for interacting with systemd is systemctl. Here's how to use it to manage services efficiently.

Understanding systemd and systemctl

systemd is a system and service manager for Linux that provides a standardized way to manage daemons, boot processes, logging, and more. It replaces older init systems like SysVinit. The systemctl command is the main interface for controlling systemd.

Services in systemd are defined by unit files (usually ending in .service), typically located in /etc/systemd/system/ or /usr/lib/systemd/system/. These files define how a service should start, stop, and behave.

Common systemctl Commands for Service Management

Here are the essential systemctl commands you’ll use daily:

• Start a service immediately

  

  sudo systemctl start nginx.service

  This runs the service now but doesn’t enable it to start at boot.

• Stop a running service

  sudo systemctl stop nginx.service

• Restart a service

  sudo systemctl restart nginx.service

• Reload a service’s configuration (without full restart)

  sudo systemctl reload nginx.service

  Useful for daemons like web servers when you change config files.

• Enable a service to start at boot

  sudo systemctl enable nginx.service

  Creates a symbolic link to the service unit in the appropriate boot target.

• Disable a service from starting at boot

  sudo systemctl disable nginx.service

Note: You can combine enable and start in one command:

sudo systemctl enable --now nginx.service

Checking Service Status and Logs

Knowing the current state of a service is crucial.

• Check if a service is running

  systemctl status sshd.service

  This shows active/inactive status, process ID, recent logs, and whether it’s enabled.

• List all active services

  systemctl list-units --type=service --state=active

• List all loaded services (including inactive ones)

  systemctl list-units --type=service --all

• View logs for a service using journalctl

  sudo journalctl -u nginx.service

  Add -f to follow logs in real time:

  sudo journalctl -u nginx.service -f

Working with Custom or Third-Party Services

If you're deploying your own application, you might need to create a custom service file.

Example: /etc/systemd/system/myapp.service

[Unit]
Description=My Custom Application
After=network.target

[Service]
Type=simple
User=myuser
ExecStart=/opt/myapp/start.sh
Restart=on-failure

[Install]
WantedBy=multi-user.target

After creating the file:

sudo systemctl daemon-reload
sudo systemctl enable myapp.service
sudo systemctl start myapp.service

Always run daemon-reload after adding or modifying a service file so systemd reloads the configuration.

Troubleshooting Common Issues

• Service fails to start?
  Check the status and logs:

  systemctl status myapp.service
  journalctl -u myapp.service --since "10 minutes ago"

• Service not found?
  Make sure the .service file is in the right directory and you’ve run daemon-reload.

• Permissions or path issues?
  Ensure scripts or binaries specified in ExecStart are executable and paths are absolute.

• Service starts but dies immediately?
  Consider using Type=oneshot or RemainAfterExit=yes for non-daemon scripts, or fix crashes in the application.

Managing services with systemctl is straightforward once you know the key commands. Whether you're starting, stopping, enabling, or debugging services, systemd provides a consistent and powerful framework. Getting comfortable with systemctl and journalctl will save you time and reduce downtime in production environments.

Basically, just remember: start, stop, enable, status, and logs — that covers 90% of what you’ll need.

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