We’ve all heard that the difference between a successful Exchange 2007 migration and a disaster is planning. That being the case, I wanted to take the opportunity to write about the types of issues that you need to think about planning for prior to a migration.
Assessing the Exchange Features that Your Organization Needs
Generally speaking, if you’re migrating from Exchange Server 2003 to Exchange Server 2007 then the migration process tends to be fairly painless. Even so, it important to keep in mind that there are some features that existed in Exchange Server 2003 that do not exist in Exchange Server 2007. Discontinued features are even more of an issue though if you are going to be migrating from Exchange 2000.
My advice is that before you even think about performing a migration, you need to take a look at the features that have been discontinued, and see if any of the discontinued features impact your organization. If you do happen to be using any of the features that have been discontinued, then you will have to figure out if you can live without the feature, or how you can implement the feature in a different way. In some cases you can maintain access to feature just by keeping a legacy Exchange Server in the Exchange organization. In other cases though, some of the discontinued features are completely unsupported in Exchange 2007 organizations.
There is no way that I can possibly talk about all of the features that have been discontinued within the confines of an article, but Microsoft does provide a list of the features that have been de-emphasized or discontinued. You can find the list here.
The nice thing about this particular list is that it not only tells you which features have been discontinued, it tells you how to work around the issue if the discontinued feature happens to be something that you still need access to. One thing to keep in mind though is that the list is not comprehensive.
The list seems to be adequate for organizations that are going to be migrating from Exchange 2003 or mixed Exchange 2000 / 2003 environments. If an organization currently only has Exchange 2000 deployed though, then there are some discontinued features that are not on the list. For example the instant messaging feature was removed in Exchange 2003, and is now a part of Office Communications Server. You can read about the Exchange 2007 features that were removed in Exchange 2003 here.
Performing a Trial Migration
One thing that I strongly recommend doing is performing a trial migration in a lab environment prior to installing Exchange 2007 in your production environment. Setting up a migration lab can be a lot of work, but in my opinion it is well worth it, because a trial migration can help you to gain experience with the migration process, and because it will help you to find out about any “surprises” ahead of time.
The key to performing a test migration is to create a lab environment that closely mimics your production network, but on a smaller scale. What I recommend doing is getting a few high end PCs with plenty of disk space and then using them to create a miniature version of your network.
You should set these computers up in a small network that is completely disconnected from your production network. You can restore full, system state backups of your production servers to the lab machines in order to get them to match your production machines as closely as possible. Of course you will probably have to do some amount of reconfiguring in order to compensate for differences in hardware.
Particular attention should be paid to the lab network’s domain controller. The lab network will not work properly unless the domain controller that you use contains the various FSMO roles, and has been designated to act as a global catalog server. Your test network will also need a DNS server to facilitate Active Directory functionality. In most cases when an organization creates an Active Directory forest, the DNS services, global catalog functionality, and all of the FSMO roles are installed on the first domain controller in the forest. Assuming that you have a domain controller that is configured in this manner, then consider using a backup of that domain controller to create the domain controller for your lab network.
In this article, I have talked about some things that you can be doing to prepare for an Exchange 2007 migration. In the next article in this series, I will discuss some more aspects to the planning process.
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