1、删除redhat原有的yum
rpm -aq|grep yum|xargs rpm -e --nodeps
2、下载yum所需要的安装包(其中XXX表示版本号)
yum-XXX.el6.centos.noarch.rpm
yum-metadata-parser-XXX.el6.x86_64.rpm
yum-plugin-fastestmirror-XXX.el6.noarch.rpm
python-iniparse-XXX.el6.noarch.rpm
有关这些包的下载地址，我们可以使用centos官方提供的镜像源（http://mirror.centos.org/），也可以使用网易提供的镜像源（http://mirrors.163.com/），针对于国内用户来说，使用网易的镜像源速度相对快一些。
第一步：首先打开网易镜像首页（http://mirrors.163.com/ ），这里我们选择centos-6这个版本，对于其他版本的redhat最好选择与其发行版本号一致的centos源
这里我们使用centos，打开链接
下面有好几个版本，我们这里使用6这个版本（如果小版本号中下面没有东西之后我们可以统一使用6这个来替代）
os下存在着我们所需要的文件
32位请选择i386，64位请选择x86_64
Packages下就是所有包的地址，从这里选择相应的包进行下载
第二步：下载所需要的rpm包，这里我们下载如下几个包（版本号可能会有不一致）
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-3.2.29-30.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-1.1.30-14.el6.noarch.rpm
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm
3、安装yum所需要的软件包
rpm –ivh python-iniparse-0.3.1-2.1.el6.noarch.rpm
rpm –ivh yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
rpm –ivh yum-3.2.29-30.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm
注意：最后两个安装包要放在一起同时安装，否则会提示相互依赖，安装失败。
4、更改yum源
cd /etc/yum.repos.d/
wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
vi CentOS6-Base-163.repo
把文件里面的$releasever全部替换为版本号，这里我们使用版本6(即把$releasever替换为6)
更改后文件的内容如下
# CentOS-Base.repo # # The mirror system uses the connecting IP address of the client and the # update status of each mirror to pick mirrors that are updated to and # geographically close to the client. You should use this for CentOS updates # unless you are manually picking other mirrors. # # If the mirrorlist= does not work for you, as a fall back you can try the # remarked out baseurl= line instead. # # [base] name=CentOS-6 - Base - 163.com baseurl=http://mirrors.163.com/centos/6/os/$basearch/ #mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=os gpgcheck=1 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6 #released updates [updates] name=CentOS-6 - Updates - 163.com baseurl=http://mirrors.163.com/centos/6/updates/$basearch/ #mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=updates gpgcheck=1 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6 #additional packages that may be useful [extras] name=CentOS-6 - Extras - 163.com baseurl=http://mirrors.163.com/centos/6/extras/$basearch/ #mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=extras gpgcheck=1 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-6 - Plus - 163.com baseurl=http://mirrors.163.com/centos/6/centosplus/$basearch/ #mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=centosplus gpgcheck=1 enabled=0 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6 #contrib - packages by Centos Users [contrib] name=CentOS-6 - Contrib - 163.com baseurl=http://mirrors.163.com/centos/6/contrib/$basearch/ #mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=contrib gpgcheck=1 enabled=0 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
5、清理yum缓存
yum clean all
yum makecache
到此为止，更改redhat更换yum源的操作就完成了。
