Munin on Centos 6 - missing perl MODULE_COMPAT_5.8.8

You are using the EPEL 5 version of the repo instead of 6, go into your /etc/yum.repos.d/epel.repo file and change:

mirrorlist=http://mirrors.fedoraproject.org/mirrorlist?repo=epel-5&arch=$basearch

to

mirrorlist=http://mirrors.fedoraproject.org/mirrorlist?repo=epel-6&arch=$basearch

Then run yum clean all and then try and install munin again.

NOTE: you may have an issue with the GPG key being different, you need to grab the EPEL6 one or just use:

yum install munin --nogpgcheck

I think you the yum configuration on the system is confused. It appears to be trying to install munin from the Centos5 (hence all of those references to '.el5') repositories instead of from a Centos6 repository and that will not work. Also once you have removed the Centos5 repositories from the configuration, be sure to run yum clean all before yum install munin.

If you have CPanel look into /etc/yum.conf and take out perl* from exclude list