I need to upgrade my Front End server to SP2 for connectivity to new mobile phones and cannot upgrade my Back End server because it is a single node in a clustered configuration (configuration developed by my predecessor). I understand that I can stand up a new Back End server and move the necessary resources out of the cluster but I don't have the physical resources or licenses to stand up an additional Exchange server. Is there a requirement to upgrade the Back End server to SP2 after the Front End server is upgraded or can I leave it at SP1?Kind Regards,Matt

Hi Matt,As you know , always recommended to have latest SP and also uniform versions on exchange through out the Exchange Infrastructure. I am sure its not going to impact mail flow. How ever you should upgrade the Back end also. even if this is single node cluster (not sure why this was done), still I am sure you can afford to have one reboot in on a week end after the SP2 installation on the BE.Raj

Thank you and I agree, I can afford the reboot, however, I cannot install the SP because the Back End server "owns" a virtual SMTP server and the upgrade fails stating that the virtual server must be failed over to another node before upgrading.Matt

Yes Matt, this is a real issue right now for you. why dont you plan either to add a second node to BE set up or get the single node cluster set up out and then bring in a stand alone set up in the infrastructure.Raj

Time (or lack of it) is the primary purpose for requiring the FE to be upgraded. I guess the question at this point is, can I uprgade the FE now, and use the BE with SP1 until I acquire the hardware resources necessary for standing up the new BE so I can migrate away from the cluster?

Yes. In fact, when applying service packs or rollups, you should always apply them to the FE first.http://support.microsoft.com/kb/328839I assume however that this is not "long-term".

Andy, Thank you for your reply. I do understand the requirement to perform the SP2 upgrade on the FE first, but will the BE function at all (even for a short term) while I acquire the resouces. I cannot find any documentation reporting if there is a requirement for performing the BE SP2 upgrade immediately after upgrading the FE so I am assuming (and everyone knows what that can lead to...) that the BE will operate in this "mixed" environment, even for a short time...

Yes, it should be fine leaving the FE at SP2 for awhile. I used to do that all the time to verify that SP2 didnt break anything. Typically you only need to upgrade everything to the same SP or rollup when its required for supportability or to take advantage of some feature.

Andy,Thank you very much for your answer and confirmation that you have done this in the past. It is unfortunate that I have to take this path but more comforting to know that someone has done this (in production) and hadn't had any issues with it.Best Regards!Matt Kitch