'Check if disk type conversion is needed.'

def _check_disk_conversion(self, image_disk_type, extra_spec_disk_type):

    if (image_disk_type == ImageDiskType.SPARSE):
        return True
    return (not (volumeops.VirtualDiskType.get_virtual_disk_type(extra_spec_disk_type) == volumeops.VirtualDiskType.EAGER_ZEROED_THICK))
