Hello, My understanding for Exchange Server 2010 about HA is that if I would like HA on both mailbox , HUB and CAS role, I need 4 physical servers (2 servers for DAG, another 2 servers for HUB and CAS with NLB). The question is that if I have only 2 physical servers without load balancer, Can I install Hyper-V on 2 physical servers and each server has 2 VMs as follows: VM for mailbox role with DAG enabled VM for HUB and CAS role with NLB. Is it possible or is it microsoft support confirmation? Regards, U37TCP

Virtual or physical are irrelevant. Virtualize all of them. Virtualize none of them. Virtualize a mix of them. It doesn't matter. Follow the guidelines for what is and is not supported (I.e. no VMotion / Live Migration etc. No SRM etc. whilst you have a DAG replicating the MBX data). Put copy one and the CAS/HT on one host and the same again on the other host. "u37tcp" wrote in message news:137346b4-0fa8-4365-ad1e-471bdb0c8326... Hello, My understanding for Exchange Server 2010 about HA is that if I would like HA on both mailbox , HUB and CAS role, I need 4 physical servers (2 servers for DAG, another 2 servers for HUB and CAS with NLB). The question is that if I have only 2 physical servers without load balancer, Can I install Hyper-V on 2 physical servers and each server has 2 VMs as follows: VM for mailbox role with DAG enabled VM for HUB and CAS role with NLB. Is it possible or is it microsoft support confirmation? Regards, U37TCP Mark Arnold, Exchange MVP.

Hello Yes you can deploy it, I configure the same scenario in my test lab, I test this case on 4 Hyper-V severs. 2 servers for DAG and 2 server with Network load balancing of HUB and CAS, Use NLB windows service for load balancing. Zafar

You can go either the Hyper-V route or simply deploy 2 physical servers each running the HT, CAS, and MBX roles. You will still be able to create a DAG with this scenerio. You will however have to deploy the File Share Witness to a third server somewhere else during DAG creation. If you pick a domain controller, there are some considerations with permissions. NLB will be required to create a CAS Array if you are running multiple CAS servers in the same AD site.