Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

We have 2 2003 Exchange servers presently, one in Canada and one in the States. They are both front end servers, we didn't want the redundancy as the connection couldn't handle the replication.

Our reseller in the states has told me that to upgrade to 2010, I will need 2 Exchange servers in the US. Is this really true? Does the CAS have to run seperately from the other roles? We only have 50 users on the box in the states, and 40 on the box in Canada. We also want to add an additional box in the UK that would hold 65 users.

share|improve this question
Just at first glance I would say 1 server could work for you. As always it depends, get your reseller to qualify their recommendations to you. It may be that they are thinking ahead and separate CAS/HT from MB for easier expansion later on, but if your business isn't growing like that then 1 server is just as easy. – Paul Cunningham Mar 15 '11 at 0:47

Assuming you're buying new server-class hardware for these Exchange 2010 servers, no you do not need two servers in a site. You want much more RAM then you had in previous versions so I would recommend 10GB of RAM minimum in that server, based on Microsoft's RAM calculations (link below). All necessary roles can run on one box (hub/mailbox/cas). You can run thousands of users on one server as long as you have enough storage space, I/O, and RAM.

Small FYI if you want a Edge Role that needs to be a separate box, and UM Role is "recommended" to be a separate box although it performs fine as an additional role on a single server in small environments like yours.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.