vSphere 5.5 supports virtual disks with up to ~62TB, so you shouldn't have issues with the 2TB virtual disk anymore (assuming the VMFS5 datastore was not upgraded from VMFS3). For earlier version, the maximum virtual disk size - in order to be able to create snapshots - is ~2,032GB (I'd recommend ~2,000GB as the maximum size). For details see http://kb.vmware.com/kb/1012384
André