配置yum源

1.安装wget

yum install -y wget

2.备份/etc/yum.repos.d/CentOS-Base.repo

cd /etc/yum.repos.d/

mv CentOS-Base.repo CentOS-Base.repo.back

3.下载阿里云的CentOS-6.repo文件

　　wget -O CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo

4.重新加载yum

yum clean all

yum makecache