OpenStack flavors include an option to set the swap space for instances. If the swap space is set to a value greater than 0, a virtual machine instance created using that flavor is instantiated with an additional disk for the swap partition.

Hardware virtualized (HVM) instances created from this type of flavor fail to boot on Oracle VM Server. Paravirtualized (PV), and hardware virtualized with paravirtualized drivers (PVHVM) instances are not affected, and boot with the additional disk assigned as the swap space.

Workaround: Delete the flavor, and create another without the swap space option. Alternatively, set the hw_disk_bus=xen property on the image, for example:

$ glance image-update --property hw_disk_bus=xen image_id

Bug: 22949662, 23148861