It has come to my attention that the PVS product guide does not clearly state that it is only the server that fails over and not the vDisk. For example, if the vDisk is on a shared store and the HA server currently providing that vDisk goes offline, another HA server (previously configured; not necessarily the server used to login) provides that same vDisk.
I edited the Managing HA chapter in the guide and removed the plural use of vDisk, which I believe may have caused that confusion. I have attached the updated version. Please read through the first few pages and let me know if this helps clarify this point.