1: modify the S/N number, make sure both Xpenology NAS are having different SN
2: modify MAC address, make sure it starts with 00:11:29:XXXXX, it is easy to change in Esxi
3: the virtual PC must have serial port ( otherwise you will see the "operation fail, please re-login again" message)
4: HA progress will be very smooth if you didn't create volume at all.
But unfortunately, it introduced a new problem.
5: it shows "operation fail, please make sure the passive server is online" if i want to create volume after HA built.
Note:
(4): if you create volume before config the HA cluster, then HA will fail