If you opt to create a PVHVM or PVM, you must ensure that all disks that the virtual machine is configured to use are configured as paravirtual devices, or they may not be recognized by the virtual machine. If you discover that a disk or virtual cdrom device is not being recognized by your virtual machine, you may need to edit the vm.cfg file for the virtual machine directly. To do this, determine the UUID of the virtual machine, and then locate the configuration file in the repository, for example on an Oracle VM Server:

# vi /OVS/Repositories/UUID/vm.cfg

Locate each disk entry that contains a hardware device such as hda, hdb, or hdc and replace with an xvd mapping, such as xvda, xvdb, xvdc etc.

Restart the virtual machine with the new configuration, to check that it is able to discover the disk or virtual cdrom device.