You can either download the full DVD or use the smaller netinstall boot image when installing CentOS 8. If you use the smaller netinstall boot image then you will get a error during setup that says ‘error setting up base repository’.

To fix this – simply enter the url: http://mirror.centos.org/centos/8/BaseOS/x86_64/os during setup. It will then find the correct repository and get the installation started.