Test Your Migration
You should always test your migration plan in a controlled laboratory setting before deploying it to your entire organization. In your test environment, you will need at least one computer for each type of operating system that you want to migrate from. For example, if you are migrating data from computers running Windows 2000 and Windows XP, you need to test at least one computer running each of these operating systems.
After you have migrated a few typical user states to the intermediate store, you should note the space required and adjust your initial calculations accordingly. You might also need to adjust the registry setting and file location information in your migration rule files. You should test the migration again after making any changes.
After you have thoroughly tested the entire migration process on a single computer, you should conduct a pilot migration with a small group of users. You should verify that all data and settings have migrated as expected. A pilot migration also gives you an opportunity to test your space estimates for the intermediate store.
Once you have determined that the pilot migration is successfully migrating the files and settings, you are ready to add USMT to the server that is running Microsoft Systems Management Server (SMS) 2003 or a non-Microsoft management technology. If you are using SMS, it is assumed that the SMS 2003 Operating System Deployment (OSD) Feature Pack has been installed on the server running SMS. For more information, see the Microsoft Web site.
For testing purposes, you can choose to create an uncompressed store using the /nocompress option. When compression is disabled, ScanState saves the files and settings to a hidden folder named "File" at StorePath\USMT3. You can use the uncompressed store to view what USMT has stored, troubleshoot a problem or you can run an antivirus utility against the files.