HPE Storage Users Group

Hi All,
Has anyone converted TPVV to fully provisioned large VLUNS. We have 12TB and 16TB VLUNS which we need to convert to fully provisioned. I understand that there is a capacity overhead during the conversion. Does anyone know what extra capacity is required?

From what i know is that the 3par creates a new full volume, copies over the data, switches the host over, and then removes the old one. so the temporary extra capacity needed would be the current size of the thin volume?