# 下载阿里云CentOS 7仓库配置sudocurl-o/etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo# 替换变量sudosed-is/\$releasever/7/g/etc/yum.repos.d/CentOS-Base.repo# 更新缓存sudoyum clean allsudoyum makecache