uname -a
cat /etc/redhat-release
cd /etc/yum.repos.d/
mv CentOS-base.repo CentOS-base.repo.bak
wget -O CentOS-base.repo http://mirrors.aliyun.com/repo/Centos-8.repo
yum makecache

uname -a
cat /etc/redhat-release
cd /etc/yum.repos.d/
mv CentOS-base.repo CentOS-base.repo.bak
wget -O CentOS-base.repo http://mirrors.aliyun.com/repo/Centos-8.repo
yum makecache