Centos7安装源地址
http://mirrors.aliyun.com/centos/7/os/x86_64/
选择软件
centos7.8下载地址:
https://archive.kernel.org/centos-vault/7.8.2003/isos/x86_64/CentOS-7-x86_64-DVD-2003.iso
centos7.7下载地址:
https://archive.kernel.org/centos-vault/7.7.1908/isos/x86_64/