Redundant Exchange Server with 3 Servers.. Not 7..

Now that Windows Server 2008 with HYPER-V and Microsoft HYPER-V Server 2008 are safely out of the door Microsoft will now offer full support for Exchange Server (and most other products) in a fully Virtualized environment. In August Microsoft published their support policies and recommendations for virtualizing Exchange (you can find these by searching google or technet). Those recommendations are ok, but frankly fall a little short on real world or advanced implementations.

What I want to cover very quickly is something that might be of use to any SME with Exchange that has thought about implementing a Highly Available solution. Lets face it, once we heard about clustering.. we all thought.. would that help my business? How difficult is this? and of course.. how much would it cost? No matter what size your business is, email is (for most) absolutley critical and whatever we can do to protect that service from failure is a worthwhile consideration.

Before the advent of HYPER-V, in order to get full redundancy for Exchange Server you would need to have 7 seperate servers. 2 for Active Directory and DNS, 1 For File and print, 2 for Client Access Services and Hub roles and another 2 servers running the mailbox mode in a CCR environment.

Fast forward to today and the exact same level of protection can be delivered with the use of only 3 servers by using Virtualization (Specifically HYPER-V). By anybodys standards thats some kind of improvement.. see the diagram below for the config: