修改Centos 6.5的yum源
1.进入目录
cd /etc/yum.repos.d/
2.保持副本
mv CentOS-Base.repo CentOS-Base.repo.backup
3.下载新的CentOS-Base.repo 到/etc/yum.repos.d/
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
4.运行yum makecache生成缓存
yum clean all
yum makecache