Question: how to rename vtd in vio?
Answer: Remove the disk from the volume group:(if not in use) reducevg vgname hdiskX.
Remove the hdisk device from ODM. rmdev -dl hdiskX.
Remove the VTD on each VIO, rmvdev -vtd <vtd name>
Create new VTD with the exact format that you want, ... 
Check the new map and device,