备份本地源mv/etc/yum.repos.d/CentOS-Base.repo/etc/yum.repos.d/CentOS-Base.repo_bak更新国内源国内源很多，一般我们选择阿里或者163阿里：http://mirrors.aliyun.com/rep...163：http://mirrors.163.com/.help/...我这里用的是阿里wget-O/etc/yum。repos.d/CentOS-Base.repohttp://mirrors.aliyun.com/repo/Centos-7.repo清除yum缓存yumcleanall重建yum缓存yummakecache更新yumyum升级
