In addition to making sure that the hardware and
server software can support Exchange Server 2010, there are a few
infrastructure requirements that you need to consider. These include
making sure that your Active Directory infrastructure can support
Exchange 2010 and that you have the necessary permissions to prepare
the forest and domain.
1. Active Directory Requirements
The actual Active Directory domain controller
requirements to install Exchange Server 2010 into your forest can be a
bit confusing. We are going to simplify this for you but also raise the
minimum bar just a bit. Here are some tips that you should follow when
ensuring that your Active Directory infrastructure will properly
support Exchange Server 2010:
All domain controllers in each Active
Directory site where you plan on deploying Exchange 2010 must be
running Windows Server 2003 SP2 at a minimum.
The Active Directory forest must be in Windows Server 2003 Forest Functional level.
Each
Active Directory site in which you will install Exchange 2010 servers
should contain at least two global catalog servers to ensure local
global catalog access and fault tolerance.
For
organizations using domain controllers running x86 Windows, each Active
Directory site that contains Exchange servers should have one domain
controller processor core for each four Exchange mailbox server
processor cores.
For organizations using domain controllers running x64 Windows and having enough RAM installed for the entire NTDS.DIT
to be loaded into memory, each Active Directory site that contains
Exchange servers should have one domain controller processor core for
each eight Exchange Mailbox server processor cores.
Always
take into account that domain controllers may not be dedicated to just
Exchange Server. They may be handling authentication for users logging
into the domain and for other applications.
Read-only
domain controllers and global catalog servers are not used by Exchange
Server 2010, so do not include their presence in your domain controller
planning.
2. Installation and Preparation Permissions
It might seem that the easiest possible way to get
Exchange Server 2010 installed is to log on to a Windows Server 2008
computer as a member of Domain Admins, Schema Admins, and Enterprise
Admins. Indeed, using a user account that is a member of all three of
those groups will give you all the rights you need.
In some larger organizations, though, getting a user
account that is a member of all three of these groups is an impossible
request. In some cases, the Exchange administrator may have to make a
request from the Active Directory forest owner to perform some of the
preparation tasks on behalf of the Exchange team. For this reason, it
is important to know the permissions that are required to perform the
different setup tasks, as shown in Table 1.
3. Coexisting with Previous Versions of Exchange Server
Exchange Server is fairly widely deployed in most
organizations, so it is likely that you will be transitioning or
migrating your existing Exchange organization over to Exchange Server
2010. For some period of time (hopefully short), your Exchange 2010
servers will be interoperating with either Exchange 2007 or Exchange
2003 servers. For this reason, you must know the factors necessary to
ensure successful coexistence.
The recommended order for installing Exchange 2010
servers and transitioning messaging services over to those new servers
is as follows:
Install
Client Access servers and decide how you will handle legacy OWA clients
(either via proxying, redirection, or direct connections). Outlook Web
Access, Windows Mobile, Outlook Anywhere, POP3, and IMAP4 clients to
the new Client Access servers.
Table 1 . Task Permissions
Task | Group Membership |
---|
PrepareLegacyExchangePermissions | Enterprise
Admins group membership or be delegated the Exchange Full Administrator
role and Domain Admins membership in each domain that has had Exchange
2003/DomainPrep executed against it |
PrepareSchema | Schema Admins and Enterprise Admins |
PrepareAD | Enterprise Admins |
PrepareDomain | Domain Admins |
Install Exchange Server 2010 | Administrators group on the Windows Server and Exchange Organization Management |
Install
Hub Transport servers and have the new Hub Transport servers take over
as much of the messages transport function as possible.
Install Mailbox servers and begin to transition mailboxes and public folders from the legacy servers to the new servers.
Install the Edge Transport servers if required and transition inbound/outbound mail through the Edge Transport servers.
Install Unified Messaging servers if required.
12.3.3.1. Coexistence with Exchange Server 2003
Prior to installing your first Exchange Server 2010
server in an organization that is running Exchange Server 2003, you
must make sure that the current organization meets some minimum
software and configuration requirements:
All Exchange 2003 servers must be running a minimum of Exchange 2003 Service Pack 2.
Each Active Directory site must have at least one global catalog server running Windows Server 2003 SP2 or later.
The Active Directory forest must be at the Windows Server 2003 Forest Functional level.
The SuppressStateChanges Registry key should be set on all Exchange 2003 servers to suppress minor state link state version changes.
The
Exchange organization must be in native mode, which means that the
Exchange 5.5 Active Directory Connector and Site Replication Service
must be removed.
All Exchange Server 2000 servers must be removed from the organization.
3.2. Coexistence with Exchange Server 2007
If you are currently using Exchange Server 2007,
prior to installing the first Exchange 2010 server ensure that you meet
the following prerequisites:
All Exchange 2007 Client Access and Unified
Messaging servers in the organization must be at Exchange Server 2007
Service Pack 2.
All Exchange 2007
servers within the Active Directory where you are planning to introduce
Exchange Server 2010 must be running a minimum of Exchange Server 2007
Service Pack 2.
The Active Directory forest must be at the Windows Server 2003 Forest Functional level.
Each Active Directory site must have at least one global catalog server running Windows Server 2003 SP2 or later.