1.删除redhat原有的yum
rpm -aq|grep yum|xargs rpm -e --nodeps
2.下载yum安装文件
注意，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。然后再下载。
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-3.2.29-69.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-1.1.30-30.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.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-3.2.29-69.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.26-11.el6.noarch.rpm
注意最后两个包必需同时安装，否则会相互依赖
－－－－－－－－－－配置网易源
4.更新repo文件
mv /etc/yum.repos.d/rhel-debuginfo.repo /etc/yum.repos.d/rhel-debuginfo.repo.repo.bak
vi /etc/yum.repos.d/rhel-debuginfo.repo
内容为：
[base] name=CentOS-5-Base #mirrorlist=http://mirrorlist.centos.org/?release=$releasever5&arch=$basearch&repo=os #baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/ baseurl=http://ftp.sjtu.edu.cn/centos/5/os/$basearch/ gpgcheck=0 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 #released updates [update] name=CentOS-5-Updates #mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=updates baseurl=http://ftp.sjtu.edu.cn/centos/5/updates/$basearch/ gpgcheck=0 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 #packages used/produced in the build but not released [addons] name=CentOS-5-Addons #mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=addons baseurl=http://ftp.sjtu.edu.cn/centos/5/addons/$basearch/ gpgcheck=0 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 #additional packages that may be useful [extras] name=CentOS-5-Extras #mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=extras baseurl=http://ftp.sjtu.edu.cn/centos/5/extras/$basearch/ gpgcheck=0 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-5-Plus #mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=centosplus baseurl=http://ftp.sjtu.edu.cn/centos/5/centosplus/$basearch/ gpgcheck=0 enabled=0 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 #contrib - packages by Centos Users [contrib] name=CentOS-5-Contrib #mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=contrib baseurl=http://ftp.sjtu.edu.cn/centos/5/contrib/$basearch/ gpgcheck=0 enabled=0 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5 # vi dag.repo [dag] name=Dag RPM Repository for RHEL5 baseurl=http://ftp.riken.jp/Linux/dag/redhat/el5/en/$basearch/dag/ enabled=1 gpgcheck=0 gpgkey=http://ftp.riken.jp/Linux/dag/packages/RPM-GPG-KEY.dag.txt
导入key
[root@linux-a ~]# rpm --import http://ftp.sjtu.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5