[root@XAYQ-Test2 yum.repos.d]# yum list
Loaded plugins: fastestmirror, priorities, product-id, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Loading mirror speeds from cached hostfile

由于 redhat的yum在线更新是收费的，如果没有注册的话不能使用，如果要使用，需将redhat的yum卸载后，重启安装，再配置其他源，以下为详细过程：
1.删除redhat原有的yum
[root@XAYQ-Test2 opt]# rpm -aq|grep yum|xargs rpm -e --nodeps

2.下载yum安装文件
[root@XAYQ-Test2 opt]# wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-3.2.29-40.el6.centos.noarch.rpm
[root@XAYQ-Test2 opt]# wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
[root@XAYQ-Test2 opt]# wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm
[root@XAYQ-Test2 opt]# wget http://mirrors.163.com/centos/6/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm

3.进行安装yum

[root@XAYQ-Test2 opt]# rpm -ivh python-iniparse-0.3.1-2.1.el6.noarch.rpm
[root@XAYQ-Test2 opt]# rpm -ivh yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
[root@XAYQ-Test2 opt]# rpm -ivh yum-3.2.29-40.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm
error: Failed dependencies:
        yum-metadata-parser >= 1.1.0 is needed by yum-3.2.29-40.el6.centos.noarch
注意最后两个包必需同时安装，否则会相互依赖