Centos7 yum镜像源

 步骤一：安装wget

yum -y install wget

 步骤二：安装阿里镜像源

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

步骤三：运行yum makecache生成缓存

yum makecache

步骤四：更新新yum

yum -y update