RHEL5.X 替换更新源
cd /etc/yum.repos.d
wget http://docs.linuxtone.org/soft/lemp/CentOS-Base.repo
mv CentOS-Base.repo rhel-debuginfo.repo
rpm --import http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
RHEL6.1替换更新源
1.移除Yum
rpm -aq|grep yum|xargs rpm -e --nodeps
2.下载Yum
wget http://mirrors.163.com/centos/6.2/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm
wget http://mirrors.163.com/centos/6.2/os/x86_64/Packages/yum-3.2.29-22.el6.centos.noarch.rpm
wget http://mirrors.163.com/centos/6.2/os/x86_64/Packages/yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
wget http://mirrors.163.com/centos/6.2/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.30-10.el6.noarch.rpm
3.安装Yum
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-3.2.29-22.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.30-10.el6.noarch.rpm
4.更新repo文件，使用网易文件
切换目录到 /etc/yum.repos.d/目录下
cd /etc/yum.repos.d/
wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
vi CentOS6-Base-163.repo
编辑文件，把文件里面的$releasever全部替换为版本号，即6 最后保存！或者直接把下面的内存拷贝到CentOS6-Base-163.repo文件中即可（已经修改好）。
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-6 - Base - 163.com
baseurl=http://mirrors.163.com/centos/6/os/$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.最后一步
yum clean all #清理yum缓存
yum makecache #将服务器上的软件包信息缓存到本地，以提高搜索安装软件的速度。
yum list yum #测试配置的yum源是否已经生效。