Processor requirments for Exchange Server 2010 roles

Question

I am looking at migrating from Exchange Server 2003 to Exchange Server 2010.  My exchange environment has 350 mailboxes.  Can anyone tell me how much processing power will be required for each exchange role to run on VMware?  I know Microsoft's recommendation is 1GB per core.

Answer 1

Hi Amyraghunath,
It's hard to give general guidance on sizing Exchange 2010 since it is heavily dependent on your specific configuration.  The key number to use for sizing the Mailbox server role is to know the number of messages sent/received per day.  That number will help you size CPU and memory for your Mailbox server which will ultimately drive the sizing for the other roles.
A good place to start is the following article: http://technet.microsoft.com/en-us/library/ee712771(v=exchg.141).aspx
That article describes the impact of messages sent/received per day has on sizing the Mailbox server and shows the math that is involved as well.  Once you know how to size the Mailbox server, you can size the other roles as well.
You can also use the Exchange Mailbox sizing calculator here ( Exchange 2010 Server Role Requirements Calculator - Exchange Team Blog - Site Home - TechNet Blogs), though be careful with this because if you aren't sure what you're entering in here you could end up with incorrect results.
Finally, here are some other great links that should be helpful to you in sizing your Exchange 2010 environment on vSphere:
http://technet.microsoft.com/en-us/library/dd346700.aspx
http://technet.microsoft.com/en-us/library/dd346699.aspx
VMware: Run Microsoft Exchange Server Software on a Virtualization Platform - United States
Hope these links help!  If not feel free to post back here.
Matt
http://www.thelowercasew.com