Identifying accounts that should not be migrated

After you have collected information about the existing users and groups in the target set of computers, examine each of the passwd and group files and NIS domain maps to create a list of users and groups that you do not plan to migrate into Active Directory. For example, in most cases, there’s no compelling business reason to migrate default system accounts, such as nfsnobdy or games, that will not map to Active Directory users. You should also eliminate accounts for people who have left your organization, and accounts that are locked or obviously invalid.