平時在安裝或更新CentOS軟件時，yum方式是最簡單方便的，而系統默認到yum更新源地址不穩定，所以需要對更新源地址進行修改，國內一般用163比較快。
yum更新源配置文件：/etc/yum.repos.d/CentOS-Base.repo
1. 在修改前先備份該文件
cp /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
2. 修改更新源配置文件（CentOS6地址，其他版本類似）
vim打開配置文件：
vim /etc/yum.repos.d/CentOS-Base.repo
復制以下內容粘貼到配置文件中進行：
# 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-$releasever - Base
baseurl=http://mirrors.oschina.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
[updates]
name=CentOS-$releasever - Updates
baseurl=http://mirrors.oschina.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
[addons]
name=CentOS-$releasever - Addons
baseurl=http://mirrors.oschina.com/centos/$releasever/addons/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
[extras]
name=CentOS-$releasever - Extras
baseurl=http://mirrors.oschina.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
[centosplus]
name=CentOS-$releasever - Plus
baseurl=http://mirrors.oschina.com/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
最後保存配置文件。
3. 更新yum源配置
yum update
（如果不願更新軟件，選擇N即可）
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
