先备份之前yum源，并清空目录cd/etc/yum.repos.d/下载阿里yum源wgethttp://mirrors.aliyun.com/repo/Centos-7.repo修改yum源链接vim /etc/yum.repos.d/Centos-7.repo替换$releasever为7:%s/$releasever/7/g清除缓存并重新生成缓存yumcleanall &&yummakecache...