yum添加网易和搜狐源

先进入yum源配置目录
cd /etc/yum.repos.d
备份系统自带的yum源
mv CentOS-Base.repo CentOS-Base.repo.save

163的yum源：

wget http://mirrors.163.com/.help/CentOS-Base-163.repo
sohu的yum源：

wget http://mirrors.sohu.com/help/CentOS-Base-sohu.repo

更新玩yum源后，建议更新一下，使操作立即生效
yum makecache

为CentOS安装EPEL软件仓库

EPEL全称: Extra Packages for Enterprise Linux.传说中最全的yum源

通过以下命令安装:

CentOS 6.x 32-bit

rpm -Uvh http://mirror.overthewire.com.au/pub/epel/6/i386/epel-release-6-7.noarch.rpm

CentOS 6.x 64-bit

rpm -Uvh http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-7.noarch.rpm

CentOS 5.x 32-bit

rpm -Uvh http://dl.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm

CentOS 5.x 64-bit

rpm -Uvh http://dl.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm

想暂停使用EPEL，在下面的文件中设置enabled=0即可.

vim /etc/yum.repos.d/epel.repo