EPEL提供的软件包大多基于其对应的Fedora软件包，不会与企业版Linux发行版本的软件发生冲突或替换其文件。

epel安装对应的rpm包

centos5 32位epel源下载地址： www.lishiming.net/data/attachment/forum/epel-release-5-4_32.noarch.rpm
64位下载地址：  www.lishiming.net/data/attachment/forum/epel-release-5-4_64.noarch.rpm
centos6
32位epel yum源下载地址： www.lishiming.net/data/attachment/forum/epel-release-6-8_32.noarch.rpm 
64位下载地址： www.lishiming.net/data/attachment/forum/epel-release-6-8_64.noarch.rpm

安装epel，执行 yum repolist测试是否成功
报错如下

[root@ZABBIX yum.repos.d]# yum repolist
Loaded plugins: product-id, refresh-packagekit, security, subscription-manager
Updating certificate-based repositories.
Error: Cannot retrieve metalink for repository: epel. Please verify its path and try again

解决方法
是编辑/etc/yum.repos.d/epel.repo，将内容调整成如下。

#baseurl
mirrorlist

改成

baseurl
#mirrorlist