How to Install Nagios XI on Ubuntu 22.04

Nagios XI is a powerful enterprise-grade monitoring tool designed to track the performance of IT infrastructure, including servers, networks, and applications. It provides real-time insights, customizable dashboards, and automated alerts, making it a critical tool for system administrators.

Install Nagios XI on Ubuntu 22.04

Prerequisites

• Ubuntu 22.04 server (minimal install recommended)
• Root or sudo privileges
• At least 4 GB RAM and 20 GB disk space
• Static IP address configured
• LAMP Stack (Apache, MySQL, PHP) will be installed automatically by the Nagios XI installer

Step 1: Update System

sudo apt update && sudo apt upgrade -y

Reboot if kernel updates are applied:

sudo reboot

Step 2: Download Nagios XI Installer

Download the latest Nagios XI installer from the official site:

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cd /tmp
wget https://assets.nagios.com/downloads/nagiosxi/xi-latest.tar.gz

Extract the archive:

tar xzf xi-latest.tar.gz
cd nagiosxi

Step 3: Run the Installer

Execute the installation script:

sudo ./fullinstall

The installer will:

1. Install required dependencies (Apache, PHP, MySQL, etc.)
2. Configure the database
3. Set up Nagios XI web interface

Step 4: Complete Web Setup

1. Access the Nagios XI web interface:

   http://your-server-ip/nagiosxi/

2. Follow the setup wizard to:

• Accept the license agreement
• Set up admin credentials
• Configure basic settings

Step 5: Get License Key (Optional)

Nagios XI requires a license for full functionality:

1. If you have a license, upload it via Admin > License Key.
2. For evaluation, use the free trial mode.

Step 6: Configure Firewall

Allow HTTP/HTTPS traffic:

sudo ufw allow 80/tcp
sudo ufw allow 443/tcp
sudo ufw reload

Step 7: Verify Installation

Check services:

sudo systemctl status nagios
sudo systemctl status apache2
sudo systemctl status mysql

Key Post-Installation Steps

1. Secure MySQL:

   sudo mysql_secure_installation

2. Set Up Email Alerts:
   Configure SMTP in Admin > Notification Settings.
3. Add Monitoring Targets:
   Use the web interface to add hosts/services.

Upgrade Nagios XI

To update to newer versions:

cd /tmp
wget https://assets.nagios.com/downloads/nagiosxi/xi-latest.tar.gz
tar xzf xi-latest.tar.gz
cd nagiosxi
sudo ./upgrade

Uninstall Nagios XI

To completely remove:

sudo ./uninstall

Important Notes

• Default Credentials:
• Web Interface: nagiosadmin / password set during installation
• Configuration Files:
• Main Config: /usr/local/nagios/etc/
• Web Interface: /var/www/html/nagiosxi/
• Logs: /usr/local/nagios/var/log/

Troubleshooting

1. Port Conflicts:
   Ensure Apache (port 80/443) is not blocked.
2. PHP Errors:
   Verify PHP extensions are installed:

   sudo apt install php-cli php-gd php-mysql php-curl

3. Database Issues:
   Check MySQL/MariaDB service status and credentials in:

   /usr/local/nagiosxi/html/config.inc.php

For official documentation, visit Nagios XI Docs.