cloud-init is a common and comfortable way to configure a virtual machine in an automated way. With cloud-init no-cloud datasource it's possible to provide user-data and meta-data to the instance without any particular network setup or service: meta-data and user-data should be exposed to the VM via files on a vfat or iso9660 filesystem. So the idea is to let the user attach an optional iso image for cloud-init to the the VM he is going to start. It could be really useful to automatically configure an appliance. So, if the user select to boot the engine VM from a disk image, the setup will ask to the user if he also want to provide an optional ISO image for clud-init. If so the setup will boot the VM from disk attaching the ISO image; this step is only necessary on the first boot on the first host. No action is required on further boots or on additional hosts.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHEA-2016-0375.html