We have our 2007 CCR cluster running on Windows Server 2003 SP2. We have Rollup Update 5 installed which was suppose to fix the issue with OAB not generating while failed over to the secondary node. We get the following error: OALGen is running on a cluster continuous replication (CCR) node which does not have registry value 'SYSTEM\CurrentControlSet\Services\MSExchangeSA\Parameters\{clusternodename}\EnableOabGenOnThisNode' or it is not set to this node name.If I manually set the key to the correct node name then everything works fine. I thought theUpdate 5was suppose fix this problem. Are there any extra configuration steps I missed to have this registry key updated automatically?

Hi Corey, I would like to explain that this is an expected error if the primary CCR node is temporarily unavailable. I suggest you review the Scenario 2 of the following article: OAB Generation on a cluster server fails with event id 9395 or 9396 http://blogs.msdn.com/dgoldman/archive/2007/02/08/oab-generation-on-a-cluster-server-fails-with-event-id-9395-or-9396.aspx Please understand the OAB related issue fixed in RU5 is that the Exchange 2007 CAS cannot copy the OAB from the OAB share on Windows Server 2008-based Exchange 2007 CCR clusters. http://support.microsoft.com/kb/954197/en-us Description of Update Rollup 5 for Exchange Server 2007 Service Pack 1 http://support.microsoft.com/kb/953467/en-us Mike

Mike, I cannot thank you enough for responding. I'm glad I didn't miss anything. When our initial exchange 2007 install was completed (Before I came to this company.) They were told that the Addressbook Generation Failure when running on the second CCR node was a known bug with exchange 2007 and would be fixed with a future update. You are the first person I've had tell me that this is an expected error when you fail to the secondary node. It would be nice if there was a way to include that key update when you initiate a fail over. Many thanks for saving me a few more grey hairs on this "issue".