redhat 默认自带的 yum 源需要注册，才能更新，所以对于我们来说需要替换掉redhat的yum源。下文更换为网易的。
删除原有的yum
rpm -qa|grep yum|xargs rpm -e --nodeps
下载yum安装文件
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-3.2.29-81.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-1.1.30-41.el6.noarch.rpm wget http://mirrors.163.com/centos/6/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm
[注] 下载时可能会找不到文件，登录http://mirrors.163.com/centos/6/os/x86_64/ 更换相应的文件。
安装
rpm -ivh python-iniparse-0.3.-2.1.el6.noarch.rpm rpm -ivh yum-metadata-parser-1.1.-.el6.x86_64.rpm rpm -ivh yum-3.2.-.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.-.el6.noarch.rpm
[注] 最后两个包需要同时安装，因为存在相互依赖
然而在执行最后一个安装命令时，出现了如下错误：
[root@root test]# rpm -ivh yum-3.2.-.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.-.el6.noarch.rpm
warning: yum-3.2.-.el6.centos.noarch.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
error: Failed dependencies:
python-urlgrabber >= 3.9.- is needed by yum-3.2.-.el6.centos.noarch
错误原因是缺少了3.9.1-10及以上版本的python-urlgrabber的依赖，所以从http://mirrors.163.com/centos/6/os/x86_64/ 寻找所需要的包。
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/python-urlgrabber-3.9.1-11.el6.noarch.rpm
然后安装时又出错了：
[root@root test]# rpm -ivh python-urlgrabber-3.9.-.el6.noarch.rpm
warning: python-urlgrabber-3.9.-.el6.noarch.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
Preparing... ########################################### [%]
file /usr/lib/python2./site-packages/urlgrabber/grabber.py from install of python-urlgrabber-3.9.-.el6.noarch conflicts with file from package python-urlgrabber-3.9.-.el6.noarch
file /usr/lib/python2./site-packages/urlgrabber/grabber.pyc from install of python-urlgrabber-3.9.-.el6.noarch conflicts with file from package python-urlgrabber-3.9.-.el6.noarch
file /usr/lib/python2./site-packages/urlgrabber/grabber.pyo from install of python-urlgrabber-3.9.-.el6.noarch conflicts with file from package python-urlgrabber-3.9.-.el6.noarch
file /usr/lib/python2./site-packages/urlgrabber/progress.pyc from install of python-urlgrabber-3.9.-.el6.noarch conflicts with file from package python-urlgrabber-3.9.-.el6.noarch
file /usr/lib/python2./site-packages/urlgrabber/progress.pyo from install of python-urlgrabber-3.9.-.el6.noarch conflicts with file from package python-urlgrabber-3.9.-.el6.noarch
与历史版本冲突了，在rpm安装的命令中加入--force 强制安装成功：
[root@root test]# rpm -ivh --force python-urlgrabber-3.9.-.el6.noarch.rpm
warning: python-urlgrabber-3.9.-.el6.noarch.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
Preparing... ########################################### [%]
:python-urlgrabber ########################################### [%]
最后执行第三条安装命令成功：
[root@root test]# rpm -ivh yum-3.2.-.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.-.el6.noarch.rpm
warning: yum-3.2.-.el6.centos.noarch.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
Preparing... ########################################### [%]
:yum-plugin-fastestmirro########################################### [ %]
:yum ########################################### [%]
更换yum源
mv /etc/yum.repos.d/rhel-source.repo /etc/yum.repos.d/rhel-source.repo.bak vim /etc/yum.repos.d/rhel-debuginfo.repo
内容为：
[base] name=CentOS-$releasever - Base baseurl=http://mirrors.163.com/centos/6/os/$basearch/ gpgcheck= gpgkey=http://mirrors.163.com/centos/6/os/x86_64/RPM-GPG-KEY-CentOS-6 #released updates [updates] name=CentOS-$releasever - Updates baseurl=http://mirrors.163.com/centos/6/updates/$basearch/ gpgcheck= gpgkey=http://mirrors.163.com/centos/6/os/x86_64/RPM-GPG-KEY-CentOS-6 #packages used/produced in the build but not released #[addons] #name=CentOS-$releasever - Addons #baseurl=http://mirrors.163.com/centos/6/addons/$basearch/ #gpgcheck= #gpgkey=http://mirrors.163.com/centos/6/os/x86_64/RPM-GPG-KEY-CentOS-6 #additional packages that may be useful [extras] name=CentOS-$releasever - Extras baseurl=http://mirrors.163.com/centos/6/extras/$basearch/ gpgcheck= gpgkey=http://mirrors.163.com/centos/6/os/x86_64/RPM-GPG-KEY-CentOS-6 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-$releasever - Plus baseurl=http://mirrors.163.com/centos/6./centosplus/$basearch/ gpgcheck= enabled=
yum clean all 命令清除原有缓存，就成功了。
参考：
[2] RHEL6配置yum源