You've decided to take the plunge and move your organization from Novell GroupWise to Exchange 2000 Server. You face challenges such as removing the GroupWise client, configuring the new messaging server product, and installing Outlook or another Messaging API (MAPI) email client. But after you get Exchange running, the most important tasks in the GroupWise-to-Exchange migration are moving mail and calendars. Let's discuss how to use the Exchange Server Migration Wizard, which installs with Exchange, to achieve these steps. (For a list of the tricks I've learned from working with the Migration Wizard, see the sidebar "Lessons Learned," page 2.)
Setting Expectations
Before you begin any migration, you should explain to both users and administrators how their worlds will change. If you don't take the time to convey that Outlook has a different look and feel from the GroupWise client, you'll probably hear from dissatisfied users. Moving from the GroupWise client to the Outlook client can be a life-altering change for many users. However, colleagues who use the Outlook or Outlook Express client at home might welcome the change. Regardless, you must prepare your users.
Administrators must thoroughly understand the process of migrating users' messaging data and know that during the window of coexistence (i.e., when both mail systems are running), the email infrastructure will be complex. End-user training is vital. Be sure to fully explain any new features, and for reassurance, point out any aspects of the new client that are the same as or better than what your users are used to.
The Migration Wizard
The Migration Wizard extracts user data—mail and calendars—from GroupWise. (The Migration Wizard can't migrate GroupWise archives, Personal Address Books—PABs—and contacts. To help you move these components, consider using ComAxis's UniAccess; visit http://www.comaxis.com for more information about this product.)
The Migration Wizard lets you perform your migration as either a one- or two-step process. If you choose the one-step method, you run the wizard once to extract and import data into Exchange. If you choose the two-step process, you must run the wizard twice: The first time, the wizard writes all data to a location you specify (typically, the local hard disk); the second time, the wizard imports the mail from the temporary location into Exchange. Use the two-step process if the one-step process fails or if you want to separate the migration into phases so that you can work with the data before importing it into Exchange. The one-step process doesn't always succeed with large mailboxes. In my experience, the two-step process is more reliable for migrating GroupWise mailboxes larger than 300MB. The two-step process might also be a better choice if your GroupWise server is ailing and the wizard has a hard time maintaining a connection with the server.
Migration Wizard Internals
Whichever process you choose, the extraction steps are similar. The Migration Wizard extracts data from GroupWise and writes the data to a temporary directory. The wizard uses Intermediate File Format (IFF) files for all migrations. IFF files are comma-separated value (CSV) files that you can view with any text editor. The wizard writes data to IFF files as it extracts the information from GroupWise. If you're migrating a large post office (or user) that contains gigabytes of data, your IFF files will also be gigabytes in size. You can identify the three IFF file types by their extensions:
- Packing List (.pkl)—The .pkl file is a list or inventory of all other IFF files relating to a migration session. The wizard uses this list as a reference for all the IFF files involved in the migration session. The wizard consults the .pkl file when you perform the second step of a two-step migration.
- Primary (.pri)—One .pri file exists for each user, and one .pri file exists for the directory information for all users. If, for example, you're migrating five users, you create six .pri files. Directory.pri contains a list of the exported users and their properties (e.g., display name, alias, addressing). The other .pri files contain the users' email messages and are named in numbered sequence (e.g., 00000001.pri, 00000002.pri).
- Secondary (.sec)—The wizard uses .sec files to hold large amounts of data, such as the body of a message or message attachments. The .pri files contain pointers to data in .sec files. In other words, a user's .pri file contains message properties such as To, From, Cc, Subject, Date, and Time. The file also includes a pointer that references a specific byte within a .sec file for the beginning of a message's body text. The wizard stores any message that exceeds 256 bytes in a .sec file and inserts a pointer to this data in the .pri file (some parts of messages, such as the body, are always stored in the .sec file, even if they're smaller than 256 bytes).