Code review comment for lp:~salvatore-orlando/nova/bug723301

Thanks for the clarification of what's going on here. That makes my life much easier. Perhaps consider putting that in a comment somewhere? :)

Great branch by the way! Much needed.

Minor style point: I think there're supposed to be a space after the hash in:
 # Comment ...

Easy changes:

433 + if len(vm_create_error.args) > 0:
434 + last_arg = vm_create_error.args[len(vm_create_error.args) - 1]
if vm_create_error.args:
   last_arg = vm_create_error.args[-1]

same thing in 455-456, 475, 479

465 + if vdi_to_remove != None:
if vdi_to_remove:

Set WIP so I can approve afterwards ...