C-A-C-T-I

Here are the dependencies of CACTI
-httpd
-net-snmp
-mysql-server
-msyql
-php
-rrdtool

yum install mysql-server mysql php-mysql php-pear php-common php-gd php-devel php php-mbstring php-cli php-snmp php-pear-Net-SMTP httpd net-snmp-utils net-snmp-libs perl-rrdtool rrdtool net-snmp

configure php
configure snmp
configure mysql
configure cacti

MAKE SURE services is running

Apply Patches..