1、查看當前Linux操作系統RedHat 版本號與32/64位操作系統。
[root@localhost CentOS5]# more /etc/redhat-release
Red Hat Enterprise Linux Server release 5.8 (Tikanga)
[root@localhost centos5]# uname -a
Linux localhost.localdomain 2.6.18-308.el5 #1 SMP Fri Jan 27 17:17:51 EST 2012 x86_64 x86_64 x86_64 GNU/Linux
2、刪除RedHat自帶的yum服務
[root@localhost centos5]# rpm -qa|grep yum |xargs rpm -e --nodeps
3、下載相應的yum 安裝包並安裝（安裝包個數因操作系統版本號不同會有存在差異）
[root@localhost centos5]# wget http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-3.2.22-40.el5.centos.noarch.rpm
[root@localhost centos5]# wget http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-fastestmirror-1.1.16-21.el5.centos.noarch.rpm
[root@localhost centos5]# wget http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-metadata-parser-1.1.2-4.el5.x86_64.rpm
[root@localhost centos5]# rpm -ivh yum*.rpm
4、配置yum源(推薦使用的是163的鏡像)
[root@localhost centos5]# vi /etc/yum.repos.d/CenOS-Base.repo
添加以下內容：
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
baseurl=http://mirrors.163.com/centos/5/os/x86_64/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/5/os/x86_64/RPM-GPG-KEY-CentOS-5
#released updates
[updates]
name=CentOS-$releasever - Updates
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
baseurl=http://mirrors.163.com/centos/5/updates/x86_64/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/5/os/x86_64/RPM-GPG-KEY-CentOS-5
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
baseurl=http://mirrors.163.com/centos/5/extras/x86_64/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/5/os/x86_64/RPM-GPG-KEY-CentOS-5
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
baseurl=http://mirrors.163.com/centos/5/centosplus/x86_64/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.163.com/centos/5/os/x86_64/RPM-GPG-KEY-CentOS-5
#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
baseurl=http://mirrors.163.com/centos/5/contrib/x86_64/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.163.com/centos/5/os/x86_64/RPM-GPG-KEY-CentOS-5
5、清除緩存並下載新的鏡像緩存
[root@localhost centos5]# yum clean all
[root@localhost centos5]# yum makecache
6、測試（查看當前subversion版本與檢查服務器subversion版本）
[root@localhost yum.repos.d]# rpm -qa|grep subversion
subversion-1.6.11-7.el5_6.4
subversion-1.6.11-7.el5_6.4 [root@localhost yum.repos.d]# yum check-update subversion
Loaded plugins: fastestmirror, katello, product-id, subscription-manager
Updating certificate-based repositories.
Unable to read consumer identity
Loading mirror speeds from cached hostfile
subversion.i386 1.6.11-12.el5_10 base
subversion.x86_64 1.6.11-12.el5_10 base
Obsoleting Packages
centos-release.x86_64 10:5-11.el5.centos base
redhat-release.x86_64 5Server-5.8.0.3 installed
firefox.i386 31.3.0-4.el5.centos updates
firefox.i386 3.6.26-1.el5_7 installed
firefox.x86_64 31.3.0-4.el5.centos updates
firefox.x86_64 3.6.26-1.el5_7 installed
7、安裝yum注意問題
根據Linux 的版本號安裝相應的CentOS並引用CentOS版本號對應的CenOS-Base.repo文件,
（1）、如果安裝了CentOS 5的yun，卻引用CentOS6的源yum makecache時就會報錯。
（2）、如果操作系統是RedHat 5，卻安裝 CentOS6 yum會導致安裝時需要手動安裝與升級大量的依賴包。
8、附：CentOS中國鏡像網址
Asia China Zhejiang University http://mirrors.zju.edu.cn/centos/
Asia China Alibaba Cloud Computing http://mirrors.aliyun.com/centos/
Asia China Beijing Institute of Technology http://mirror.bit.edu.cn/centos/
Asia China BitComm Ltd. http://mirrors.pubyun.com/centos/
Asia China CDS China http://mirrors.yun-idc.com/centos/ ftp://mirrors.yun-idc.com/centos/ rsync://mirrors.yun-idc.com/centos/
Asia China China University of Geosciences http://mirrors.cug.edu.cn/centos/
Asia China Dalian Neusoft University of Information http://mirrors.neusoft.edu.cn/centos/ ftp://mirrors.neusoft.edu.cn/centos/
Asia China Huazhong University of Science and Technology http://mirrors.hust.edu.cn/centos/ rsync://mirrors.hust.edu.cn/centos/
Asia China NetEase http://mirrors.163.com/centos/
Asia China Northeastern University, Shenyang Liaoni http://mirror.neu.edu.cn/centos/
Asia China Northwest A&F University http://mirrors.nwsuaf.edu.cn/centos/
Asia China Qiming College of Huazhong University of Science and Technology http://mirrors.hustunique.com/centos/ rsync://mirrors.hustunique.com/centos/
Asia China Shanghai Jiao Tong University http://ftp.sjtu.edu.cn/centos/ ftp://ftp.sjtu.edu.cn/centos/
Asia China Sohu Inc, Beijing P.R. China http://mirrors.sohu.com/centos/
Asia China University of Science and Tech of China http://centos.ustc.edu.cn/centos/
Asia China - Hong Kong Asia Web Services Ltd. http://mirror.vpshosting.com.hk/pub/linux/centos/ ftp://mirror.vpshosting.com.hk/pub/linux/centos/
CentOS中將DVD作為默認yum源的設置方法 http://www.linuxidc.com/Linux/2015-01/111266.htm
RedHat 6.2 Linux修改yum源免費使用CentOS源 http://www.linuxidc.com/Linux/2013-07/87383.htm
配置EPEL YUM源 http://www.linuxidc.com/Linux/2012-10/71850.htm
Redhat 本地yum源配置 http://www.linuxidc.com/Linux/2012-11/75127.htm
yum的配置文件說明 http://www.linuxidc.com/Linux/2013-04/83298.htm
RedHat 6.1下安裝yum(圖文) http://www.linuxidc.com/Linux/2013-06/86535.htm
YUM 安裝及清理 http://www.linuxidc.com/Linux/2013-07/87163.htm
CentOS 6.4上搭建yum本地源 http://www.linuxidc.com/Linux/2014-07/104533.htm
更多RedHat相關信息見RedHat 專題頁面 http://www.linuxidc.com/topicnews.aspx?tid=10