Hello Dear, we currently have 6 servers serving Exchange 2007 in the following roles: 2 Servers in NLB mode for HUB-CAS Role + 2 Servers serving UM Mode + 2 Servers serving Mailbox Role in SCC Mode As per the new requirement Management wants to merge all the roles in any 2 servers (for redundancy). Pls let me know, how practical it is to achieve this and if "Yes" what need to be done to achieve it (with the least amount of overhead). I would really appreciate any input on the above matter and look forward to your valuable support. Regards

With Exchange 2007 Mailbox HA (SCC and CCR), only the mailbox role can be installed on the server. So you cannot combine any roles onto the MB servers. You could install the UM role on your HUB/CAS servers and get rid of 2 servers. In Exch 2010 this changes. You can have full HA with all roles installed on 2 servers.Tim Harrington - Catapult Systems - http://HowDoUC.blogspot.com

With Exchange 2007 Mailbox HA (SCC and CCR), only the mailbox role can be installed on the server. So you cannot combine any roles onto the MB servers. You could install the UM role on your HUB/CAS servers and get rid of 2 servers. In Exch 2010 this changes. You can have full HA with all roles installed on 2 servers. Tim Harrington - Catapult Systems - http://HowDoUC.blogspot.com I agree with Tim, but right now you got a good configuration, i would suggest for no change. You may explain your management accordingly. +++++++++++++++ Even with E2010 you can run M+H+C on the same box but when talk about HA (High availability for all servers roles its not a right configuration) if the database *over to a different server or the Active Server goes down it requires manual intervention to take care of the failure to take care CAS (Client connectivity) NOTE: UM role on a DAG member is not supported by MS -------------- So to achieve great availability you need at least 2 MBX servers in DAG (Hub can co-exist) 2 CAS in CAS array (for CAS HA) or 1 CAS without HA 1 or 2 UM as per your requirement Regards, Hari | MCSE+ Messaging

Thanx Tim and Hari for your valuable input. My further query is.....as per the recommendation from Tim if i move the UM roles from both the servers to the HUB-CAS servers....would such situation be OK ??? knowing that HUB-CAS are in NLB mode. In other words will UM roles also be supported on HUB_CAS servers which are functioning in NLB mode.

In Exchange 2007, the clustered mailbox role must be by itself. So you could not do this. In exchange 2010, you can have all the roles on there (except edge which must be by itsef), but you cannot combine NLB on a node that is a mailbox server member of a DAG. You can,, however use an external hardware loadbalancer and combine the roles down to two servers (plus the external hardware load balancer. John b