Customer had originally installed Unity 3.1 VM with failover: 1 - Exchange server/member server, 1 Primary Unity/DCGC, 1 Failover Unity/DCGC.
They say this architecture was supported by Cisco at the time of install and they have upgraded to 4.05 2 years ago.
They now want to replace the primary server with new hardware and update to 4.2.
I checked and see in the 4.x Design Doc that running DC on Unity failover servers is NOT supported by Cisco.
I advised rebuilding all 3 servers as per the Cisco spec: either run DC on the Exchange or on a 4th box.
They do not want to change the setup. I do not want to proceed as is if I cannot get TAC support if the server replacement has issues.