本人使用的方法一，成功配置，方法二没测过，可以作为参考
方法一：
1.确保RHEL5中已经安装了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
(如果目录下没有.repo文件自己创建一个)
[base] name=CentOS-5-Base #mirrorlist=http://mirrorlistcentosorg/"htmlcode">＃rpm --import http://ftp.sjtu.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-54. 运行，测试
＃yum update5.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 该文件内容如下： [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以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。