Nagios monitoring tools...

Because the nature of my job as System Engineer, and also as Administrator for my division, which running 24x7 so I must know which computer that having sluggish performance, before the computer became useless in daily operational.
My division is a collaboration between Indonesia company and a Dutch based company..well they outsource some of their task to my division, including monitoring task, they use BMC Patrol for monitoring their customer environment.
BMC Patrol is a powerful tools,but is very expensive.Because I only need to monitoring my division environment, so I must use a cost free tools (because there is no way the management will permit me to buy a monitoring tools), and after googling i found a monitoring tools that called nagios.I like nagios because it a great tools with free of charge, and the most important it's open source.Nagios can monitor anything on your computer with the help of its plugin. There are lots of plugin for nagios, such as plugin to monitor mysql server, Citrix, Oracle, CPU, memory, etc. Well there are lots of plugin for nagios, so it's almost imposibble to mention then one by one. You can find nagios at their web www.nagios.org, there are documentation for that, and also you can use google to find help when you stuck with nagios.

But when you installing nagios from the source you must have lot of patient and read the documentation over and over again.
For me I use the rpm package from rpmforge, only need to run the yum command, then the nagios automatically installed on your system.
After you installed then you must configure the nagio configuration file, and what I like from linux is the configuration file use text, and not registry like the one you find a windows system.Because I use centos as the nagios server I use the guide from Max Hetrick at the centos wiki here the web http://wiki.centos.org/HowTos/Nagios. Because nagios not provide a graphic output so you need an add-on to generate chart, for this i use pnp(PNP is not PerfParse ), it's a great tools and quite easy to installed.

Because all the computer at my division ia a windows machine (except for the nagios server), i use the NSClient++ at the windows machine, and at the nagios server I use check_nt plugin. You can monitor all the counter you can find at windows performance counter. To see which counter available at your computer just use the perfmon snap-in. For start see this link http://nagios.sourceforge.net/docs/3_0/monitoring-windows.html.