HI, I have a design implementation question. We would like to upgrade from 2007 & 2010 to 2013. We are a small firm with only 50 AD users and about 60-70 mailboxes all on Exchange 2007. I thought about moving a few mailboxes over to 2010, but decided not doing so since I want to upgrade to 2013. Our current 2007 server has all roles installed all on one server. I know in Exchange 2013 there are only 2 roles And I guess my question to everyone is should I implement 2 servers with both roles on each server and setting up a CAS Array/DAG/High Availability accordingly or should I separate the roles out and implement 4 servers total so that would be 2 dedicated CAS servers & 2 dedicated Mailbox servers and setting up CAS Array/DAG/High Availability accordingly. Any recommendations? Thoughts? Server specs: HP DL380 Gen8 32 GIGS-Ram 500 GIGS-HD Our current 2007 store is about 120 gigs in total. Any advice or comments would be appreciated. Thanks! J

Hi, Since you have very less number of mailboxes i would say you can go with 2 servers.Kottees : My Blog : Please mark it as an answer if it really helps you.

Thank you!!! so go with the 2 servers and both roles installed on both?

you are most welcome, yes. Because Exchange 2013 server single database can go upto 2 TB, 50 DB x 2 TB = 100 TB. For 60 - 70 mailboxes it is VERY less :-)Kottees : My Blog : Please mark it as an answer if it really helps you.

Agree. 4 servers for 50 users? That's close to a 1 server to 10 user ratio. How much email does the average user send and receive a day? Are very large attachments typical? You might be better off with two servers in a DAG configuration and perhaps hardware load-balancing (would have to see prices on the Kemp units for example - and not sure you might benefit from special pricing - .gov or .edu for example). Of course, if money is not really an issue (cost of servers plus licensing...), sure ,you could have that many servers if you want. Please mark as helpful if you find my contribution useful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you.

Great! Thanks again.