Nagios ( is a popular open source computer system and network monitoring software application. It watches hosts and services, alerting users when things go wrong 
and again when they get better.
Nagios was originally designed to run under GNU/Linux, but also runs well on other Unix variants. It is free software, licensed under the terms of the GNU General Public License version 2 as published by the Free Software Foundation.
In our previous posts, we did show you how to install Nagios from source in Ubuntu, today we wil see together how to install Nagios in one command.
First install Step we will install nagioa3 package using the command :
sudo apt-get install nagios3
Now after download is done. insert the password of nagiosadmin user
After the installation open thebrowser http://localhost/nagios3 and insert the login admin and the password inserted in the step before
Now you can check your monitored services and you can make more monitoring configuration for your Server
Enjoy
