Yum镜像源

vim /etc/yum.repos.d/CentOS-Base.repo

移动改名

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak

从https://mirrors.aliyun.com/repo/Centos-7.repo下载Centos-7.repo  命名为CentOS-Base.repo
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo

Yum源已经改成阿里

vim /etc/yum.repos.d/CentOS-Base.repo