# Revision history [back]

You are missing a disk because by default, Nova doesn't create one in addition to the image. You only have one storage device, namely the CD ROM.

In order to make this work, you need to tell Nova explicitly to map a volume or ephemeral disk to the instance. As an example how to use a volume, see https://docs.openstack.org/mitaka/user-guide/cli_nova_launch_instance_using_ISO_image.html. This is for Mitaka, but should work for Ocata as well (I didn't find an Ocata version of that page).

The key is the block-device option. In the example:

source=blank,dest=volume,size=10,shutdown=preserve


means that you create a disk from nothing (source=blank) on a volume (dest=volume) with the given size, and ensure that the volume persists after deleting the instance. I am not sure if the Ocata version of the openstack client is able to do that; in Pike, it is, though the block device parameters are a bit different if I remember well.

To better understand block device mapping, read https://docs.openstack.org/nova/latest/user/block-device-mapping.html.