1、刪除以前的yum源
rpm-qa|grepyum|xargsrpm-e--nodeps
2、從http://centos.ustc.edu.cn/centos/5.4/os/i386/CentOS/下載以下文件並安裝
yum-fastestmirror-1.1.16-13.el5.centos.noarch.rpm
yum-3.2.22-20.el5.centos.noarch.rpm
yum-updatesd-0.9-2.el5.noarch.rpm
或者找個FTP站點用wget下載：
#wgetftp://ftp.pdc.kth.se/pub/bambi/centos/5.4/os/i386/CentOS/yum-fastestmirror-1.1.16-13.el5.centos.noarch.rpm
#wgetftp://ftp.pdc.kth.se/pub/bambi/centos/5.4/os/i386/CentOS/yum-3.2.22-20.el5.centos.noarch.rpm
#wgetftp://ftp.pdc.kth.se/pub/bambi/centos/5.4/os/i386/CentOS/yum-updatesd-0.9-2.el5.noarch.rpm
3、#rpm-ivhyum*.rpm
4、cd/etc/yum.repos.d
編輯CentOS-Base.repo,填入以下內容
######################
[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
###################
5、一個完整的yum源就完成了