更换yum源为阿里云源
1.复制备份: cp /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup 2.下载: wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo "-bash: wget: 未找到命令"-解决办法: yum -y install wget 3.生成缓存: yum makecache 如果失败 先运行: yum clean all 来源: https://www.cnblogs.com/ooo0/p/11820781.html