If you want to update the yum repository on Centos 5 server then follow the below steps :
root@server[#] yum install yum-fastestmirror
root@server[#] yum install yum-priorities
root@server[#] uname -i
If the output is i386 then
root@server[#] cd /usr/local/src
root@server[#] wget http://apt.sw.be/redhat/el5/en/i386/rpmforge/RPMS/rpmforge-release-0.3.6-1.el5.rf.i386.rpm
Install key
root@server[#] rpm –import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt
Install rpmforge
root@server[#] rpm -ivh rpmforge-release-0.3.6-1.el5.rf.i386.rpm
root@server[#] yum check-update
Note : It may take some time to update the RPM and yum can create the file named “primary.xml.gz”
After that you will be able to install any software using yum command
for example yum install mplayer* , yum install ffmpeg etc.
