yum install wget
wget -c http://mirrors.163.com/centos/7.5.1804/isos/x86_64/CentOS-7-x86_64-DVD-1804.iso
wget -c --limit-rate=1000k http://mirrors.163.com/centos/7.5.1804/isos/x86_64/CentOS-7-x86_64-DVD-1804.iso
原文：https://www.cnblogs.com/xzlive/p/9724286.html