I have to migrate from exchange 2003 to 2010 or 2013, this is the setup

Forest n Domain Functional Level: Win 2003

GC/DC : Win 2003

Exchange : Clustered Exchange 2003 Std

Mailbox : 170 Users

My domain is a child domain, the parent and other child domains are also using exchange 2003 only.

i have 2 new servers, my plan is , install win 2012 with HyperV , create 2 VM for each server.

Host1 : VM 1: Exchange 2010 MBX , VM2: Exchange 2010 CAS/HT

Host2: VM 3: Exchange 2010 MBX , VM4: Exchange 2010 CAS/HT

Create DAG for VM1&3, create Client Access Array for VM 2 & 4

Is it possible ? do i need a witness server for DAG?

Appreciate for all help !

You'll need to go to 2010 unless you want to build out another AD forest as well. 2013 cannot coexist with 2003 for the migration period. You will need a witness for the DAG otherwise you won't be able to keep quorum if one node fails. I'd recommend that you place that on another server in your environment that is not hosted on the same VM hosts as exchange. In your particular architecture, loosing the wrong host could take one node and the FSW offline.

Are you planning to use Windows Network Load Balancing? or do you have a load balancer in the environment? If no WNLB, you may want to consider combining the three roles rather than splitting out the CAS/Hub onto another VM.

Hi DK,

Yep, i'll go to 2010. My primary intention is to have HA for exchange 2010.

I don't have hardware or third-party load balancer. I'll use Windows Network Load Balancing.

You mean I can install all three roles on one VM, how can i get HA for that?

Thanks,

DAG (windows clustering) and WNLB are incompatable and cannot be installed on the same VM. If you had intended on using a hardware load balancer, you could have setup two VMs both with all three roles installed. Then setup a DAG to get HA. Again though, since your using WNLB, that's not possible. Hope that helps.

Ok, is my first plan workable ? 4 VM on 2 Physical server.

Host1 : VM 1: Exchange 2010 MBX , VM2: Exchange 2010 CAS/HT

Host2: VM 3: Exchange 2010 MBX , VM4: Exchange 2010 CAS/HT

Create DAG for VM1&3, create Client Access Array for VM 2 & 4

OR is there another way to get HA without hardware loadbalancer ? Like 2 VM with all 3 roles installed, use windows clustering or something to get HA.

Actually i'm not familiar with clustering or WNLB.

Thanks,

Sorry if I wasn't clear. Your plan is fine. You will get HA by creating a DAG with the two mailbox servers. Your CAS array will use Windows Network Load Balancing (WNLB) to give you CAS HA. Transport HA is built into the hub transport.

OK, Thanks. For witness server , can i use existing server like DC ? Any requirements for witness server ?

Exchange will try to select a Hub, but you can use anything. Just be mindful when performing maintinence.