1.首先备份/etc/yum.repos.d/CentOS-Base.repo

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup

2.下载网易的repo文件

wget img/20170809/stbyzpd014a.repo  

放入/etc/yum.repos.d/(操作前请做好相应备份)

mv CentOS6-Base-163.repo /etc/yum.repos.d/CentOS-Base.repo

3.修改 CentOS-Media.repo，把 baseurl 改成  baseurl=http://mirrors.163.com/centos/$releasever/os/$basearch/ 

vi /etc/yum.repos.d/CentOS-Media.repo

4.运行以下命令生成缓存

yum clean all 
yum makecache