Open a browser with webmin interface http://serverip:100000
Go Webmin --> Webmin configuration --> Webmin Modules
Copy this link on Third Party Modules
Then Install it
The package installed will be called Historic System Statistics
If you click on that you will get an error because there are some packages missing.
The missing package is RRDtool. You can get it from different sources however I suggest you
to use rpmforge repos.
Go System --> Software Packages and copy this link on (From ftp or http URL)
Then you would have to clean yum database.
Go Others --> Command Shell and run yum clean all
Then go back to System --> Software Packages
On (Packages from Yum) : rrdtool perl-libwww-perl
Finally go System --> Historic System Statistic
The modules start to configure themselve and then Start Webminstats.
Now you can have stats and trends running on the server without using external tools.