挺好用的，之前用腾讯云安装了半天，太慢了，改过之后速度快多了。
1、首先备份系统自带yum源配置文件/etc/yum.repos.d/CentOS-Base.repo
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
2、下载ailiyun的yum源配置文件到/etc/yum.repos.d/
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-8.repo
3、运行yum makecache生成缓存
yum makecache
4、这时候再更新系统就会看到以下mirrors.aliyun.com信息
yum -y update
已加载插件：fastestmirror, refresh-packagekit, security
设置更新进程Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com