说明：
redhat的yum在线更新是收费的，如果没有注册的话是不能使用的。可以将redhat自带的yum卸载重新rpm安装，再配置其他第三方源。第三方源包括：网易，epel,repoforge ,rpmfusion。后面试了下，不必要卸载原来的yum，可以直接跳到第4步，修改rhel-debuginfo.repo也可以使用。
实现：
1.删除redhat原有的yum。
# rpm -aq|grep yum|xargs rpm -e --nodeps
2.下载yum源安装包，如果下载时找不到文件，就登录到：http://mirrors.163.com/centos/6/os/x86_64/上查找相应的文件下载。
# cd /usr/local/src # 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
我这里是RHEL 6 64位的，因此如下安装。RHEL 5，6可以参考附录1：CentOS 5，6 yum包（32位对应32位安装包，64位对应64位安装包）
3.进行安装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-3.2.29-30.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm //注意最后两个包必需同时安装，否则会相互依赖
4.更新repo文件，配置为163网易源
# mv /etc/yum.repos.d/rhel-debuginfo.repo /etc/yum.repos.d/rhel-debuginfo.repo.repo.bak //备份源文件 # 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$releasever全部替换为版本号，本系统为cat /etc/issue Red Hat Enterprise Linux Server release 6.0，所以将$releasever全部替换为6后保存！
当然，手动输入以下内容也是可以的
# 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.测试yum是否可用
# 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 info vsftd //测试yum是否可用
附录：
附录1：CentOS 5，6 yum包（32位对应32位安装包，64位对应64位安装包）
CentOS5
32位版的：
wget http://mirrors.ustc.edu.cn/centos/5/os/i386/CentOS/python-iniparse-0.2.3-6.el5.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/5/os/i386/CentOS/yum-3.2.22-40.el5.centos.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/5/os/i386/CentOS/yum-metadata-parser-1.1.2-4.el5.i386.rpm
wget http://mirrors.ustc.edu.cn/centos/5/os/i386/CentOS/yum-fastestmirror-1.1.16-21.el5.centos.noarch.rpm
64位版的：
wget http://mirrors.ustc.edu.cn/centos/5/os/x86_64/CentOS/python-iniparse-0.2.3-6.el5.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/5/os/x86_64/CentOS/yum-3.2.22-40.el5.centos.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/5/os/x86_64/CentOS/yum-metadata-parser-1.1.2-4.el5.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/5/os/x86_64/CentOS/yum-fastestmirror-1.1.16-21.el5.centos.noarch.rpm
CentOS6
32位版的：
wget http://mirrors.ustc.edu.cn/centos/6/os/i386/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/6/os/i386/Packages/yum-3.2.29-40.el6.centos.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/6/os/i386/Packages/yum-metadata-parser-1.1.2-16.el6.i686.rpm
wget http://mirrors.ustc.edu.cn/centos/6/os/i386/Packages/yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm
64位版的：
wget http://mirrors.ustc.edu.cn/centos/6/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/6/os/x86_64/Packages/yum-3.2.29-40.el6.centos.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/6/os/x86_64/Packages/yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/6/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm