原文链接：http://blog.csdn.net/kimyoungvon/article/details/53103300
RHEL6解决无法使用YUM源问题
问题如下：
[root@bogon ~]# yum repolist
Loaded plugins: product-id, refresh-packagekit, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
repolist: 0
或者# yum install ntp
Loaded plugins: product-id, refresh-packagekit, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Setting up Install Process
Nothing to do
解决方法：
1.清除原有RHEL的YUM及相关软件包。
rpm -qa | grep yum | xargs rpm -e --nodeps
rpm -qa |grep python-urlgrabber|xargs rpm -e --nodeps
2.下载centos6的相关软件包。
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-3.2.29-73.el6.centos.noarch.rpm
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.30-37.el6.noarch.rpm
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/python-urlgrabber-3.9.1-11.el6.noarch.rpm
*注释:这些软件包的具体的版本，请到http://mirrors.163.com/centos/6/os/x86_64/Packages/ 目录下，选择下载上述软件包。网上很多文章没法直接使用就是因为软件包的版本问题。
3.安装软件包。
rpm -ivh python-iniparse-0.3.1-2.1.el6.noarch.rpm
rpm -ivh python-urlgrabber-3.9.1-11.el6.noarch.rpm
rpm -ivh yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
rpm -ivh yum-plugin-fastestmirror-1.1.30-37.el6.noarch.rpm yum-3.2.29-73.el6.centos.noarch.rpm
*注释yum-plugin-fastestmirror和yum-3.2.29要一起安装。
如果按照遇到问题：发现错误，python-urlgrabber版本必须大于等于3.9.1-10
# rpm -ivh yum-3.2.29-73.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.30-37.el6.noarch.rpm
warning: yum-3.2.29-73.el6.centos.noarch.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
error: Failed dependencies:
python-urlgrabber >= 3.9.1-10 is needed by yum-3.2.29-73.el6.centos.noarch
查看系统的python信息
# rpm -qa|grep python
发现python-urlgrabber-3.9.1-9.el6.noarch 版本低于3.9.1-10
卸载：python-urlgrabber-3.9.1-9.el6.noarch
rpm -e python-urlgrabber-3.9.1-9.el6.noarch
安装：rpm -ivh python-urlgrabber-3.9.1-11.el6.noarch.rpm
安装yum
# rpm -ivh yum-*
更改yum源
cd /etc/yum.repos.d/
下载配置文件
wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
将此配置文件替换/etc/yum.repos.d同名文件
sed -i "s;\$releasever;6;g" CentOS6-Base-163.repo
mv rhel-source.repo rhel-source.repo.bak
或者编辑配置文件
#vim CentOS-Base.repo
把$releasever替换成现有系统的版本号(6)
vim替换命令
：%s/$releasever/6/g
退出保存
清理yum缓存
#yum clean all
将服务器软件包信息缓存至本地，提高搜索安装效率
#yum makecache