http://mirrors.aliyun.com/repo/
cd /etc/yum.repos.d
mv CentOS-Base.repo CentOS-Base.repo.backup
wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
mv CentOS6-Base-163.repo CentOS-Base.repo
yum clean all
sed -i ‘s/$basearch/x86_64/g’ /etc/yum.repos.d/CentOS-Base.repo