Spend the weekends trying to get Cacti up and running on this VPS. Apparently since this VPS is using WHM on CentOS, there are some packages like Apache, PHP, MYSQL, Perl, Ruby installed directly but not indicated as installed via Yum and hence it is failing dependency check when trying to install rrdtool.

What is Cacti

Blog - UsersOnline (Custom)
Blog – UsersOnline (Custom)