The Nagios plugin check_multi is a convenient tool to execute multiple checks within a single check command that generates an overall returned state and output from it. Here in this recipe, we will show you how to set it up and use it to quickly monitor a list of important system metrics on your clients.
It is assumed that you've gone through this chapter recipe by recipe, therefore by now, you should have a Nagios server running and another client computer that you want to monitor, which can already be accessed via its NRPE service externally by our Nagios server. This client computer that you want to monitor needs an installation of the CentOS 7 operating system with root privileges and a console-based text editor of your choice installed on it, as well as a connection to the Internet in order to facilitate the download of additional packages. The client computer will have the IP address 192.168.1.8.