Here we add a few additional repositories to Centos 5.

=== install yum priorities ===

First, install the Yum Priority package, which protect the base Centos 5 components from being overwritten.

yum install yum-priorities

Edit the /etc/yum.repos.d/CentOS-Base.repo file, add priority=1 to each of the sections [base], [addons], [updates], [extras]

vi /etc/yum.repos.d/CentOS-Base.repo

Update the system and make sure the yum-priorities is working

yum update

Should see the output include “loading priorities plugin …… 99999 packages excluded due to repository priority protection”…

=== Install RPMForge (DAG) ===

for i386
rpm -Uvh http://apt.sw.be/redhat/el5/en/i386/RPMS.dag/rpmforge-release-0.3.6-1.el5.rf.i386.rpm

for x86_64
rpm -Uvh http://packages.sw.be/rpmforge-release/rpmforge-release-0.3.6-1.el5.rf.x86_64.rpm

=== Install EPEL ===

for i386
rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-3.noarch.rpm

fro x86_64
rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/x86_64/epel-release-5-3.noarch.rpm

=== Example ===
Many additional packages will be available after adding the above repos, for example: install a zabbix-agent package:

yum list zabbix*
yum install zabbix-agent