Nagios

Nagios is a trusted and most powerful Linux monitoring tool that offers complete monitoring of Linux distributions. It monitors the parameters like system metrics, process state, service state, CPU load and file system usage. It also detects the protocol failures and network outages. It can be installed under the directory called /usr/local/nagios and it offers flexibility, scalability and task simplicity. It holds two monitoring tools such as Nagios core and Nagios XI. Its special feature is that it gives an alert to the system administrator, if anything goes wrong in the system.