"Nagios: System and Network Monitoring" shows how to configure and use Nagios, an open source system and network monitoring tool. Nagios makes it possible to continuously monitor network services (SMTP, POP3, HTTP, NNTP, PING, etc.), host resources (processor load, disk and memory usage, running processes, log files, etc.), and environmental factors (such as temperature). When Nagios detects a problem, it communicates the information to the sys admin via email, pager, SMS, or other user-defined method; current status information, historical logs, and reports can also be accessed via a web browser. "Nagios System and Network Monitoring" covers the Nagios core, all standard Nagios plug-ins and selected third-party plug-ins, and shows readers how to write their own plug-ins. The book covers Nagios 2.0 and is backwards compatible with earlier versions.