centos快速配置yum源
cd /etc/yum.repo.d/
mkdir allbak
mv * allbak/
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
cd /etc/yum.repo.d/
mkdir allbak
mv * allbak/
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo