Migrate to Exchange 2007/2010 on same hardware

Method of upgrading to Exchange 2007/2010 on the same hardware as you currently have Windows 2003/Exchange 2003 installed in a single server environment. (It is assumed that DNS/DHCP/Exchange/DC are all installed on the same server).

NOTES:
This method is not suitable for migrating Small Business Server (SBS). (Article coming soon!)

Never run DCPROMO on a server that currently has any version of Exchange installed on it, it will break Exchange.  The reason for this is Exchange relies on IIS and running DCPROMO makes changes to IIS and the way it functions; therefore running DCPROMO on an Exchange server will result in at the very best a re-install of Exchange

It is recommended that Exchange is not installed on a Domain Controller for the reasons documented here: http://technet.microsoft.com/en-us/library/aa997407(EXCHG.80).aspx. With this in mind, as you are rebuilding a server you may want to consider, and I would highly recommend, using a virtualisation product to seperate your Exchange Server and Domain Controller. If your server's CPU(s) have Hypervisor support (most recent server-grade and even high end desktop-grade CPUs do), free Hypervisor products like VMWare ESXi http://www.vmware.com/products/esxi/ and Microsoft Hyper-V Server http://www.microsoft.com/hyper-v-server/en/us/default.aspx make this much more realistic and will help seperate your servers with little additional hardware cost.

TERMS:
GC = Global Catalog Server
DC = Domain Controller
VM = Virtual Machine
PM = Physical Machine

To be able to upgrade Windows 2003/Exchange 2003 on the same hardware you first need a temporary server. This can either be a Virtual Machine (VM) or a reasonable specification workstation or an old server that is no longer being used.  In this example we are going to use a VM and I am going to call it TEMPEXCH.

If you are going to virtualise upon a workstation, I would recommend VMWare Server or Microsoft Virtual PC.

The process I will outline below involves introducing a new Windows 2003/Exchange 2003 server into your infrastructure. The reason for this is because Exchange 2007/2010 requires a 64-bit platform for installation which limits the options for VMs and older physical machines.

1) Using either of the 2 Virtualisation products above, or another product of your choice, create a new VM (or use your Physical Machine) and install Windows 2003.

2) Configure the networking so that your TEMPORARY Exchange Server is using the CURRENT Domain Controller for DNS.

3) Run DCPROMO on your TEMPORARY Exchange Server and select the option to Install an Additional Domain Controller. Complete the remaining wizard screens with the default settings.

4) Make sure that your TEMPORARY Exchange Server is also a Global Catalog Server: in Active Directory Sites and Services, expand the DC, right click NTDS Settings and check the box (allow at least 15 minutes for the Global Catalog data to be built and the server to begin advertising as a GC).

5) Install the DNS role on the TEMPORARY Exchange Server and update the network configuration so it is now using its own IP address for DNS. If it is an AD integrated zone, DNS will replicate automatically. If it's not an AD Integrated DNS, you can do the following to change this:

               a.       In the DNS Console right click on the forward lookup zone and select Properties.
               b.       Where it says Type click Change
               c.       And then ensure the check box for “Store this zone in Active Directory is checked”

6) Install Exchange 2003 server onto the TEMPORARY Exchange Server and migrate all your mailboxes, public folders etc, over to the TEMPORARY Exchange 2003 server (do not DCPROMO the current server whilst Exchange is on it) as per: http://support.microsoft.com/kb/822931 (Don't follow the "Remove the first Exchange Server 2003 Computer" section yet).

7) Update your firewall/router rules to ensure that port 25 for SMTP and port 443 for Outlook Web Access are configured to the TEMPORARY Exchange Server.

8) Leave both Exchange Servers running for a day or 2 to allow all clients to update then decommission the CURRENT Exchange Server as per the "Remove the first Exchange Server 2003 Computer" section in the following article: http://support.microsoft.com/kb/822931.

9) Once Exchange is uninstalled from the CURRENT Exchange Server move all the FSMO roles to the server that will remain when you rebuild as per: http://support.microsoft.com/kb/324801

10) DCPROMO CURRENT Exchange Server to remove Active Directory, then remove it from the network and rebuild with Windows 2008 or Windows 2008 R2. This must be the 64-bit version; there is no 32-bit version of Exchange 2010, and the 32-bit version of Exchange 2007 is not supported for use in production.

11) Run DCPROMO to make the new server a Domain Controller, clicking the Advanced link on the first screen to Install DNS as part of the configuration.

12) Install all pre-requisites for Exchange 2010 as per http://technet.microsoft.com/en-us/library/bb691354.aspx. Please note the different script for a Server 2008 R2 host system.

13) Install Exchange 2007/2010 move all mailboxes, replicate public folders etc.
               a.      Move mailboxes as per: http://technet.microsoft.com/en-us/library/bb124495.aspx
               b.      Move Public Folders as per: http://technet.microsoft.com/en-us/library/bb331970(EXCHG.80).aspx

14) Update firewall rules to ensure that port 25 for SMTP and port 443 for Outlook Web Access point to the new Exchange 2007/2010 Server.

15) Leave both servers running together for a few days to allow clients to update then decommission your TEMPORARY Exchange 2003 server as per:  http://technet.microsoft.com/en-us/library/bb288905(EXCHG.80).aspx.

Further reading:

Upgrading to Exchange 2010: http://technet.microsoft.com/en-us/library/aa998604.aspx