【From】 https://www.cnblogs.com/lpbottle/p/7875400.htmlhtml
1. 備份原來的yum源緩存
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backupcurl
2. 下載阿里雲的CentOS-Base.repo 到/etc/yum.repos.d/阿里雲
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repourl
3. 清理緩存htm
sudo yum clean allblog
4. 生成新的緩存下載
sudo yum makecacheyum