Centos
http://mirrors.aliyun.com
http://mirrors
.sohu.com
http://mirrors.163.com
https://mirrors.tuna.tsinghua.edu.cn/centos/
Ubuntu
http://cdimage.ubuntu.com/releases/ Server版
https://mirrors.tuna.tsinghua.edu.cn/ubuntu-cdimage/releases/
http://releases.ubuntu.com/ Desktop版
http://mirrors.aliyun.com/ubuntu-releases/
https://mirrors.tuna.tsinghua.edu.cn/ubuntu-releases/
