平时在安装或更新CentOS软件时，yum方式是最简单方便的，而系统默认到yum更新源地址不稳定，所以需要对更新源地址进行修改，国内一般用163比较快。
yum更新源配置文件：/etc/yum.repos.d/CentOS-Base.repo
1. 在修改前先备份该文件
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，，其他版本类似）
vim打开配置文件：
vim /etc/yum.repos.d/CentOS-Base.repo
复制以下内容粘贴到配置文件中进行：
# 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-$releasever – Basebaseurl=http://mirrors.oschina.com/centos/$releasever/os/$basearch/gpgcheck=1gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
[updates]name=CentOS-$releasever – Updatesbaseurl=http://mirrors.oschina.com/centos/$releasever/updates/$basearch/gpgcheck=1gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
[addons]name=CentOS-$releasever – Addonsbaseurl=http://mirrors.oschina.com/centos/$releasever/addons/$basearch/gpgcheck=1gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
[extras]name=CentOS-$releasever – Extrasbaseurl=http://mirrors.oschina.com/centos/$releasever/extras/$basearch/gpgcheck=1gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
[centosplus]name=CentOS-$releasever – Plusbaseurl=http://mirrors.oschina.com/centos/$releasever/centosplus/$basearch/gpgcheck=1enabled=0gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
最后保存配置文件。
3. 更新yum源配置
yum update
（如果不愿更新软件，选择N即可）
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本文永久更新链接地址：
也有伤心的，既有令人兴奋的，也有令人灰心的，
