Nagios History.

I want to know about the “NAGIOS” the server monitoring tool. It looks like weird for a fresh learners regarding the server maintainance. I just wanna information about the “NAGIOS” and the activity it can perform on the server.

Sol:
NAGIOS   –   NETWORK MONITORING  SYSTEM

NAGIOS AUTHOR: Ethan Galstad
NAGIOS stands for: NAGIOS AIN’T GONNA INSIST ON SAINTHOOD
What is nagios ?

Nagios is a host and service monitor designed to inform us of network
problems before our clients, end-users or managers do. It has been
designed to run under the Linux and Windows operating system. The
monitoring daemon runs intermittent checks on hosts and services we
specify using external “plugins” which return status information to
Nagios. When problems are encountered, the daemon can send
notifications out to administrative contacts in a variety of different ways
(email, instant message, SMS, etc.). Current status information,
historical logs, and reports can all be accessed via a web browser.

NAGIOS FEATURES:
Some of the features of Nagios are listed below:
 * Monitoring of network services (SMTP, POP3, HTTP, PING, etc.)
 * Monitoring of host resources (processor load, disk and memory usage,
running processes, log files, etc.)
 * Monitoring of environmental factors such as temperature
 * Simple plugin design that allows users to easily develop their own host
and service checks
 * Contact notifications when service or host problems occur and get
resolved (via email, pager, or other user-defined method)
 * Ability to define event handlers to be run during service or host
events for proactive problem resolution
 * Scheduled downtime for suppressing host and service notifications
during periods of planned outages