本人使用的方法一，成功配置，方法二沒測過，可以作為參考

方法一：

1.確保RHEL5中已經安裝了yum

[root@lvs-master ~]# rpm -qa |grep yum yum-metadata-parser-2-el5 yum-updatesd-9-el5 yum-22-el5 yum-security-16-el5 yum-rhn-plugin-4-el5 

2.修改源配置文件 ＃vim /etc/yum.repos.d/CentOS-Base.repo

(如果目錄下沒有.repo文件自己創建一個)

[base] name=CentOS-5-Base #mirrorlist=http://mirrorlistcentosorg/?release=$releasever5&arch=$basearch&repo=os #baseurl=http://mirrorcentosorg/centos/$releasever/os/$basearch/ baseurl=http://ftpsjtueducn/centos/5/os/$basearch/ gpgcheck=1 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-centos5 #released updates [update] name=CentOS-5-Updates #mirrorlist=http://mirrorlistcentosorg/?release=4&arch=$basearch&repo=updates baseurl=http://ftpsjtueducn/centos/5/updates/$basearch/ gpgcheck=1 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-centos5 #packages used/produced in the build but not released [addons] name=CentOS-5-Addons #mirrorlist=http://mirrorlistcentosorg/?release=4&arch=$basearch&repo=addons baseurl=http://ftpsjtueducn/centos/5/addons/$basearch/ gpgcheck=1 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-centos5 #additional packages that may be useful [extras] name=CentOS-5-Extras #mirrorlist=http://mirrorlistcentosorg/?release=4&arch=$basearch&repo=extras baseurl=http://ftpsjtueducn/centos/5/extras/$basearch/ gpgcheck=1 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-centos5 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-5-Plus #mirrorlist=http://mirrorlistcentosorg/?release=4&arch=$basearch&repo=centosplus baseurl=http://ftpsjtueducn/centos/5/centosplus/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-centos5 #contrib - packages by Centos Users [contrib] name=CentOS-5-Contrib #mirrorlist=http://mirrorlistcentosorg/?release=4&arch=$basearch&repo=contrib baseurl=http://ftpsjtueducn/centos/5/contrib/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-centos5 # vi dagrepo [dag] name=Dag RPM Repository for RHEL5 baseurl=http://ftprikenjp/Linux/dag/redhat/el5/en/$basearch/dag/ enabled=1 gpgcheck=1 gpgkey=http://ftprikenjp/Linux/dag/packages/RPM-GPG-KEYdagtxt 

3. 導入key

＃rpm --import http://ftp.sjtu.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5 

4. 運行，測試

＃yum update 

5.clean操作

#yum clean all 

方法二：

# cd /etc/yum.repos.d/ #mv CentOS-Baserepo CentOS-Baserepobak #wget http://docslinuxtoneorg/soft/lemp/CentOS-Baserepo 該文件內容如下： [base] name=CentOS-5 - Base baseurl=http://centosustceducn/centos/5/os/$basearch/ gpgcheck=1 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-CentOS-5 #released updates [update] name=CentOS-5 - Updates baseurl=http://centosustceducn/centos/5/updates/$basearch/ gpgcheck=1 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-CentOS-5 #packages used/produced in the build but not released [addons] name=CentOS-5 - Addons baseurl=http://centosustceducn/centos/5/addons/$basearch/ gpgcheck=1 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-CentOS-5 #additional packages that may be useful [extras] name=CentOS-5 - Extras baseurl=http://centosustceducn/centos/5/extras/$basearch/ gpgcheck=1 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-CentOS-5 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-5 - Plus baseurl=http://centosustceducn/centos/5/centosplus/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-CentOS-5 #contrib - packages by Centos Users [contrib] name=CentOS-5 - Contrib baseurl=http://centosustceducn/centos/5/contrib/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-CentOS-5 #packages in testing [testing] name=CentOS-5 - Testing baseurl=http://centosustceducn/centos/5/testing/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrorcentosorg/centos/RPM-GPG-KEY-CentOS-5