This shell script for Nagios to check free memory on your Linux machines, this can support to CentOS, Fedora, Ubuntu Families and etc.

This post describes to install and configure Nagios Client on Ubuntu system, You need to updates necessary packages, install libtool, openssl, libssl dev.

If you may receiving the following errors from the nagios alert, Return code of 255 is out of bounds.

I hope you know to install Nagios monitoring server on CentOS, this post describes to configure the Nagios client in Ubuntu machine. very simple steps to install,

We have already described Nagios installation, Client configuration in the last post, this is explain to service group configure in Nagios server.

If you may get an error cannot find SSL libraries, while configuring NRPE for Nagios

-e or --expect option is monitoring http response code, at least one of them is expected in the first line of server response httpd 1.x.