下载163的yum源到本地
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo
清除缓存
yum clean all
生成缓存
yum makecache
添加yum源
原文：https://www.cnblogs.com/tz90/p/12398907.html
