Ubuntu systemctl Basics: status / start / restart / enable (Troubleshooting Guide)

systemctl Basics - Service Management Troubleshooting
Reading time: ~8 min Level: Intermediate

What You'll Learn

  • How to manage services (Nginx/Apache/SSH etc.) with systemctl on Ubuntu
  • How to troubleshoot "not working", "need restart", "need auto-start" issues quickly
  • Standard patterns for incident response

Quick Summary

Master these commands and you'll handle most situations:

  • Check status: systemctl status <service>
  • Start: systemctl start <service>
  • Stop: systemctl stop <service>
  • Restart: systemctl restart <service>
  • Reload config: systemctl reload <service> (if supported)
  • Enable auto-start: systemctl enable <service>
  • Disable auto-start: systemctl disable <service>

On Ubuntu, most commands require admin privileges, so add sudo.

Table of Contents

  1. What is systemctl?
  2. Start with "status"
  3. start/stop/restart
  4. reload / reload-or-restart
  5. Auto-start (enable/disable)
  6. Troubleshooting "not working"
  7. Finding Service Names
  8. Common Pitfalls

Prerequisites

  • OS: Ubuntu
  • systemd environment
  • Permissions: sudo access

1. What is systemctl?

systemctl is the systemd service management command.
You can start/stop/restart/check status of services running on the server (e.g., nginx, apache2, ssh, docker).

2. Start with "status"

Troubleshooting always starts here.

$ sudo systemctl status nginx

Key indicators:

  • Active: active (running) → Running
  • Active: inactive (dead) → Stopped
  • Active: failed → Failed (needs investigation)

For failed status, check logs with journalctl -u - that's the fastest path.

3. start/stop/restart

3-1. Start

$ sudo systemctl start nginx

3-2. Stop

$ sudo systemctl stop nginx

3-3. Restart

$ sudo systemctl restart nginx

After config changes, use restart.
If the service supports reload, you can use reload to apply changes without downtime.

4. reload / reload-or-restart

4-1. reload (only for supported services)

$ sudo systemctl reload nginx

4-2. reload-or-restart (safe fallback)

$ sudo systemctl reload-or-restart nginx
  • Uses reload if supported
  • Falls back to restart otherwise

5. Auto-start (enable/disable) - Common Beginner Issue

"It's running now, but stops after reboot" - this is the problem.

5-1. Enable auto-start

$ sudo systemctl enable nginx

5-2. Disable auto-start

$ sudo systemctl disable nginx

5-3. Check auto-start status

$ systemctl is-enabled nginx

Output:

  • enabled: Auto-start ON
  • disabled: Auto-start OFF

6. Troubleshooting "not working"

6-1. Check status

$ sudo systemctl status nginx

6-2. If failed, check logs (fastest path)

$ sudo journalctl -u nginx -n 200

Real-time tracking:

$ sudo journalctl -u nginx -f

6-3. Check config syntax first (e.g., nginx)

$ sudo nginx -t

If you restart with broken config, the service may stay down.
Check syntax first → restart if OK is the safe approach.

7. Finding Service Names

Service names vary by environment (e.g., Apache is apache2 on Ubuntu).

Search from list:

$ systemctl list-units --type=service | grep -i apache

List all (many results):

$ systemctl list-units --type=service

8. Common Pitfalls

8-1. status shows "running" but can't access

Even if the service is running, port binding, firewall, or application errors can prevent access.
Combine with "port connectivity (ss/lsof/nc/curl)" troubleshooting for faster resolution.

8-2. Enabled but not running

enable means "auto-start on next boot".
To start now, you also need start.

$ sudo systemctl enable nginx
$ sudo systemctl start nginx

Summary (Copy-Paste Template)

# Check status
sudo systemctl status <service>

# Start/Stop/Restart
sudo systemctl start <service>
sudo systemctl stop <service>
sudo systemctl restart <service>

# Reload config (if supported)
sudo systemctl reload <service>
sudo systemctl reload-or-restart <service>

# Auto-start
sudo systemctl enable <service>
sudo systemctl disable <service>
systemctl is-enabled <service>

# Logs
sudo journalctl -u <service> -n 200
sudo journalctl -u <service> -f

Related Articles

Test Environment

Commands in this article were tested on Ubuntu 24.04 LTS / bash 5.2.

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