Nagios remains a cornerstone of Linux system performance monitoring, offering unmatched flexibility and reliability. By mastering its setup and configuration, administrators can ensure their systems ...

depends on your install. I think the default is in a mysql database called nagios. It can also be in postgres sql (my preference) or several other back ends.

After you configure what hosts and services you want to monitor, Nagios schedules regular checks against that host and/or service. If it finds a problem, Nagios does the following: the Nagios site ...