修改Centos安装软件包的源

1、进入存放源配置的文件夹
cd /etc/yum.repos.d
2、备份默认源
mv ./CentOS-Base.repo ./CentOS-Base.repo.bak
3、使用wget下载163的源
wget http://mirrors.163.com/.help/CentOS-Base-163.repo
把下载下来的文件CentOS-Base-163.repo设置为默认源
mv CentOS-Base-163.repo CentOS-Base.repo
或者手动输入
vi CentOS-Base.repo
修改如下：
（CentOS 6.X的用户请自行将RPM-GPG-KEY-CentOS-5改为RPM-GPG-KEY-CentOS-6）
[base]
name=CentOS-$releasever – Base
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
baseurl=http://centos.ustc.edu.cn/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
#released updates
[updates]
name=CentOS-$releasever – Updates
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
baseurl=http://centos.ustc.edu.cn/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever – Addons
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=addons
baseurl=http://centos.ustc.edu.cn/centos/$releasever/addons/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
#additional packages that may be useful
[extras]
name=CentOS-$releasever – Extras
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
baseurl=http://centos.ustc.edu.cn/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/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=$basearch&repo=centosplus
baseurl=http://centos.ustc.edu.cn/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
4、最后使用 yum update 测试并刷新缓存。