I'm trying to understand the minimum required number and roles of VM required to host Exchange 2010 on an IaaS cloud platform.
NOTE: I'm talking about number of guests. Not number of physical boxes I'm hosting guests on. This is CLOUD. I want to draw a diagram and label guests and their roles.
What are the minimum roles involved and how can they be consolidated per virtual machine guest? You need a global catalog AD server, client access server, hub transport server, mailbox server, right? I'm not sure what can be combined into a single virtual host.
This isn't a HA scenario, so there's no failover or load balancing. Just the bare minimum to get Exchange serving for one or multiple domains. I can build best practice and HA off this minimal skeleton later.
Bonus round: What about Small Business Server? That combines AD and Exchange in a single box, doesn't it? This might be an alternative answer.