Installing Exchange Server 2010 in an Exchange Server 2003 environment (part 1)

• All domains in the existing Active Directory forest containing Exchange Recipients have to be running in native mode.

• The Active Directory forest has to be running on a Windows Server 2003 forest functionality level.

• Each site in Active Directory should have at least one Domain Controller, and the Global Catalog server needs to be on a Windows Server 2003 SP2 level. Although not required, it is recommended to have 64-bit type Domain Controllers and Global Catalog Servers for best performance.

• The Schema Master of the Active Directory needs to be a Windows Server 2003 SP2 or Windows Server 2008 server. This can be either a 64-bit or an 32-bit server.

• All Exchange 2003 servers must have Service Pack 2 installed.

In addition to that, the server where Exchange Server will be installed also needs to meet the following prerequisites:

• The server needs to be a 64-bit computer.

• Windows Server 2008 SP2 or Windows Server 2008 R2 64-bit needs to be installed.

• Internet Information Server needs to be installed.

• Windows Remote Management (WinRM) 2.0 needs to be installed.

• PowerShell 2.0 needs to be installed.

• .NET Framework 3.5 SP1 needs to be installed.

Depending on the version of Windows 2008 you're using (i.e. Service Pack 2 or R2), a number of hotfixes will also need to be installed. I would strongly recommend that you bring your server up to date with the latest hotfixes from Microsoft Update, preferably before you perform this installation.

To make the process of installing prerequisites as painless as possible, the Exchange Server product group has created a series of XML files that can be used to automatically install Internet Information Server on your computer, together with the other prerequisites for Exchange Server 2010. These files are located on your installation media in the "scripts" directory.

To install the Internet Information Server (and other prerequisites) in a configuration needed to support, for example, an Exchange Server 2010 Client Access Server, you can use the "Exchange-CAS.xml" file with the following command:

If you are using Windows Server 2008 R2, you will get a warning about ServermanagerCmd.exe being deprecated under Windows Server 2008 R2, but it still works fine – go ahead and run it.

Figure 1. Use ServerManagerCmd.exe to install Internet Information Server.

1 Exchange Server 2010 order of installation

Although Exchange Server 2010 can be installed into an existing Exchange Server 2003 environment – in the same forest and the same domain – there are some issues with compatibility, and you have to take the installation order of the Exchange Server 2010 servers into account.

• First – Exchange Server 2010 Client Access Server. The Client Access Server can work with an Exchange Server 2003 Mailbox Server as well as an Exchange Server 2010 Mailbox Server.

• Second – Exchange Server 2010 Hub Transport Server. Between the Hub Transport Server and the Exchange 2003 (front-end) server, a so called "Interop Routing Group Connector" will be created to enable SMTP messages to be sent back and forth between the two environments.

• Third – Exchange Server 2010 Mailbox Server role. After you've installed the Mailbox Server role and established a proper Public Folder replication between Exchange Server 2003 and Exchange Server 2010, you can start moving mailboxes to the new Mailbox Server.

• The Exchange Server 2010 Edge Transport Server role can be installed at any time during the upgrade, but the Edge Transport Server features are only fully available when the Exchange Server Hub Transport Server is installed.

2 Installing Exchange Server 2010

Although you will need to install each of the Exchange Server 2010 server roles in a specific order, these roles can of course be combined on one machine.

Installing Exchange Server 2010 into an existing Exchange Server 2003 environment is pretty straightforward. The process can be broken down into the following easy steps:

• Exchange Server readiness check (as part of the Best Practices Analyzer).

• Upgrading the Active Directory Schema.

• Upgrading the Exchange organization.

• Upgrading the Active Directory domain.

• Installing the first Exchange Server 2010 server.

When you start the GUI setup application of Exchange Server 2010 (setup.exe), all these steps will be performed automatically in the correct order. I'll go through them in more detail here because you can use the command-line version of setup if you want to fully control the options and execution of the setup program.

2.1 Upgrading the Active Directory

The first step in changing your configuration for Exchange Server 2010 is upgrading the Active Directory schema to the Exchange Server 2010 level. You can achieve this by opening a command prompt on the Active Directory schema master from the Exchange Server 2007 installation media, and running the following commands:

The first command, with /PrepareLegacyExchangePermissions, grants new permissions to ensure that the Recipient Update Service in Exchange Server 2003 continues to run correctly after the schema change to Exchange Server 2010 (which is performed in the next step). The /PrepareLegacyExchangePermissions must be performed before the actual upgrade of the Schema, which is what the second command does.

If you want to change the Schema on a computer that's not the Schema Master, you have to make sure that the LDIFDE application is available on that computer. You can install this by opening a command prompt and entering the following:

You can check what version your schema is, or check if the upgrade was successful, using a tool like ADSIEDIT or LDP.EXE and checking the CN=ms-Exch-Schema-Version-Pt object in the Active Directory schema. After the schema change, its "rangeUpper" property should have the value 14529 (or higher, as this value is for Beta1 of Exchange Server 2010 and will change with later versions). Just so you know, the property can have the following values:

Figure 2. Check the schema version. This schema is on the Exchange Server 2010 level.

After upgrading the Schema, the current Exchange Server 2003 organization can be upgraded to support Exchange Server 2010. To do this, run the following command from the Exchange Server 2010 installation media:

This simple command automatically configures the global Exchange objects in Active Directory (residing in the Active Directory Configuration container), creates the Exchange Universal Security Groups in the root of the domain, and prepares the current domain for Exchange Server 2010.

It also creates the Exchange 2010 Administrative Group called "Exchange Administrative Group (FYDIBOHF23SPDLT)" and Exchange 2010 Routing Group called "Exchange Routing Group (DWBGZMFD01QNBJR)" if they didn't already exist .

Figure 3. Exchange Universal Security Groups created during the /PrepareAD option.

To verify that this step completed successfully, make sure that there is a new organizational unit (OU) in the root domain called Microsoft Exchange Security Groups and that this container contains the groups shown in Figure 3.

After running the setup.com application with the /PrepareAD switch, the newly created Administrative Group will show up in the Exchange Server 2003 System Manager, as you can see in Figure 4.

Figure 4. The Exchange Server 2010 Administrative Groups shows up after running setup.com /PrepareAD.

The last step in preparing your environment for the implementation of Exchange Server 2010 is to prepare the Active Directory domain (or domains) for Exchange Server 2010. The domain is prepared by running the following command from the Exchange Server 2010 installation media:

When you have multiple domains holding Exchange Recipients in your Active Directory forest, and you want to prepare all domains in one step you can replace the /PrepareDomain with /PrepareAllDomains.

This sets the necessary permissions on the Exchange Server container in Active Directory, as well as for the Exchange Servers, the Exchange Administrators and Authenticated Users. It also creates a new Global Group called "Exchange domain servers" in the domain where the command is run. This Global Group is only used for installing Exchange Server 2010 servers in a child domain, in a site other than the root domain. The setup program uses this to avoid installation issues when the Domain Controllers haven't yet fully replicated all the updated information.

After performing these easy steps, the Active Directory and Exchange Server environment is fully prepared for the installation of the first Exchange Server 2010 server!

2.2 Installing the first Exchange Server 2010 server

In our example Exchange Server 2003 environment, we will implement a combined Exchange Server 2010 Hub Transport and Client Access Server, and a dedicated Exchange Server 2010 Mailbox Server. Both the Client Access and Hub Transport Servers will need to have Internet Information Server installed.

To install a combined Exchange Server 2010 Hub Transport and Client Access Server into the nicely prepared Exchange Server 2003 environment, you can follow these steps:

Figure 6. Select the Client Access Role and the Hub Transport Role.

Click Next to continue;

2.3 Installing the Exchange Server 2010 Mailbox Server

As we've only installed a Client Access Server and Hub Transport Server, we still need to go through the installation process for an Exchange Server 2010 Mailbox Server. The steps are very similar, but there are some small differences.