It is important to test your Nagios config changes before you try to reload or restart Nagios.
To test your configs, run /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
The key is to look for errors. Generally most warnings can be ignored, but optimally you should not have any errors or warnings.
Total Warnings: 0
Total Errors: 0
Things look okay – No serious problems were detected during the pre-flight check
If everything looks OK, you should be able to safely reload Nagios and confirm your changes in the UI.
