在RHEL_5环境,使用centos源

[base]
name=CentOS-5 - Base
repo=os
baseurl=http://centos.ustc.edu.cn/centos/5/os/$basearch/
gpgcheck=1
gpgkey=http://centos.ustc.edu.cn/centos/RPM-GPG-KEY-CentOS-5

[update]
name=CentOS-5 - Updates
baseurl=http://centos.ustc.edu.cn/centos/5/updates/$basearch/
gpgcheck=1
gpgkey=http://centos.ustc.edu.cn/centos/RPM-GPG-KEY-CentOS-5

[addons]
name=CentOS-5 - Addons
baseurl=http://centos.ustc.edu.cn/centos/5/addons/$basearch/
gpgcheck=1
gpgkey=http://centos.ustc.edu.cn/centos/RPM-GPG-KEY-CentOS-5

[extras]
name=CentOS-5 - Extras
baseurl=http://centos.ustc.edu.cn/centos/5/extras/$basearch/
gpgcheck=1
gpgkey=http://centos.ustc.edu.cn/centos/RPM-GPG-KEY-CentOS-5

[centosplus]
name=CentOS-5 - Plus
baseurl=http://centos.ustc.edu.cn/centos/5/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://centos.ustc.edu.cn/centos/RPM-GPG-KEY-CentOS-5

[contrib]
name=CentOS-5 - Contrib
baseurl=http://centos.ustc.edu.cn/centos/5/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://centos.ustc.edu.cn/centos/RPM-GPG-KEY-CentOS-5 

导入KEY文件

rpm --import http://centos.ustc.edu.cn/centos/RPM-GPG-KEY-CentOS-5 

还可以使用网易mirrors.163.com的源，只需要把上面的所有centos.ustc.edu.cn替换成mirrors.163.com即可。