Before you can perform an AD to AD Cross-Empire Data Migration, you must first perform some prerequisite tasks on the source and target servers, along with establishing a configured trust relationship between the two.
Create matching user and group objects in the target forest for objects in the source forest.
Make sure you have installed all Storage Manager for Active Directory components in the target forest.
Disable file screening and virus protection software on the target server during the migration.
Configure DNS so that the source and target forest can communicate.
Configure a forest trust between the source and target forest.
At a minimum, a one-way trust is required so that the target forest can access the source forest.
For a detailed explanation of forest trust requirements, see Section 13.1.14, Forest Trusts.
From the Utilities\CEDM folder on the Storage Manager ISO image, copy the CEDMScanCompare.exe utility to either the Windows target server or to a Windows server where you are going to administer the migration.