Comment 1 for bug 1443898

I try to replace 'device_name': 'vda' in the test by 'device_name': 'xvda', but this leads to an Exception in nova/compute/api.py InvalidBDMBootSequence. This is because boot_index is set to -1 with xvda, instead of 0.
nova is only looking for a device_name equal to 'vda' to be a root device (or root_device_name).

I've search for a way to change root_device_name and it's look like this could be in the volume image metadata 'root_device_name', but I don't know if it's possible to change within the tempest test.