Chapter 12. Migrating to Exchange 2003

Microsoft Exchange is the gorilla in the enterprise messaging market. This dominance became clear with Exchange 5.5 and has continued to grow with the introduction of Exchange 2000 and now Exchange 2003. As most readers probably know, there was a huge architectural change between Exchange 5.5 and the current architecture implemented in Exchange 2000 and Exchange 2003. This architectural change incorporated many changes to the product, of course, but the major changes can be summarized as:

• Splitting the access protocols from the information store

• The ability to partition the store into multiple storage groups and databases

• The use of Active Directory (AD) for the messaging service's Directory Service (DS).

The Exchange 2003 architecture is represented in Figure 12.1.

Figure 12.1. Exchange 2003 architecture.

The last item in the previous list, Active Directory, has been both an advantage to the new Exchange architecture as well as a hindrance. The advantages are numerous and include:

• A single directory for use by multiple applications; from an Exchange perspective, a single place to store configuration information.

• Separation of DSs (and therefore the potential delegation of authority) away from the messaging system. From an Exchange perspective, the administration of the directory and directory replication can be managed and designed completely separate from the messaging service.

• A common directory providing authentication and messaging-specific (for example, directory lookup) services. This is in contrast to Exchange 5.5, which had one directory (the Security Accounts Manager [SAM]) for authentication information and another (the Exchange DS) for messaging specific services.

There are many more advantages that can be identified. What might surprise some folks, though, is that AD Directory has been a hindrance to the adoption of Exchange 2000 and Exchange 2003 (for simplicity I will focus only on Exchange 2003 since it is the most recent version). Why has AD been an obstacle ? Simply put, Exchange 2003 requires AD and AD is a huge step forward for most Windows NT 4.0 administrators. Bottom line is, if you have a bad AD deployment (including DNS [Domain Name Server]), you will have a really poor Exchange 2003 deployment. And, because many customers have been hesitant to deploy AD, they cannot deploy Exchange 2003. Why do I bring this up? Because even though Exchange is the dominant player in the enterprise messaging space, nearly 50% of those customers are still running Exchange 5.5. So, in short, Exchange 2003's largest competitor is actually Exchange 5.5.

Microsoft is going to make the decision to move forward easy on their customers, however. Support for Exchange 5.5 ends as of December 31st, 2005. The message is clear: move forward to Exchange 2003, move to some other messaging service, or be left behind.

With this in mind, moving to Exchange 2003 will take on one of several forms:

• Exchange 5.5 to Exchange 2003

• Exchange 2000 to Exchange 2003

• Some other mail system to Exchange 2003

One thing to keep in mind is that if you've already done the planning and design work to move from Exchange 5.5 to Exchange 2000, you have already done the planning work to move to Exchange 2003. The only exception to this rule is if you were planning to take advantage of features in Exchange 2000 that are not available in Exchange 2003; the major ones being Instant Messaging and Conferencing services. Obviously, you will need to check the specific features and functions you are interested in before moving on.

There is no way to properly present everything you need to know about Exchange 2003 and migration planning in one chapter. Microsoft and HP have full curriculums of courses and training they use to teach their consultants and customers the proper steps to plan, design and implement an Exchange 2003 environment. HP provides a wide variety of Exchange-specific services ”from planning and design, to support, through to complete outsourcing of Exchange.

There are also many books out on the shelf that detail the migration planning and system administration of Exchange. You should use these resources (training, practice labs, outside consultants) before you deploy Exchange into your environment. Some specific book titles to consider are

• Microsoft Exchange 2000 Infrastructure Design by Kieran McCorry and Donald Livengood (Digital Press, 2001)

• Scaling Microsoft Exchange 2000 by Pierre Bijaoui (Digital Press, 2001)

• Monitoring and Managing Microsoft Exchange 2003 by Mike Daugherty (Digital Press, 2004)

• Microsoft Exchange 2003 by Tony Redmond (Digital Press, 2003)

• Mission-Critical Microsoft Exchange 2000 by Jerry Cochran (Digital Press, 2000)

Obviously, a lot of information is also available free at the Microsoft and HP Web sites.