Windows Server 2003 includes several new features and tools for handling domain deployments and improving interoperability. They are as follows:
Active Directory Migration Tool (ADMT) improvements.
The new version of ADMT supports password migration, retains access to user profiles, and greatly simplifies re-permissioning of member servers and desktops.
While NT and Windows 2000 domain controllers remain operational, many new Windows Server 2003 features must be kept disabled. The new features are phased into operation using a set of functional levels. Two of these functional levels mimic the Mixed and Native operation of Windows 2000. The remaining two functional levels enable Windows Server 2003 features first in a domain then in the forest.
Application naming contexts.
This feature was mentioned in Chapter 5, "Managing DNS," but it bears repeating here. A Windows Server 2003 domain controller is capable of storing Active Directory Integrated DNS zone records in separate Application naming contexts. This gives much more flexibility to the design of Windows-based DNS in a large enterprise.
Domain controller overload prevention.
Windows 2000 and XP desktops prefer to do their logons at Active Directory-based domain controllers. This can cause problems early in a deployment when the number of desktops may be out of proportion to the number of new domain controllers. A special Registry entry can be enabled at the Windows Server 2003 domain controllers so that they emulate classic backup domain controllers (BDCs) until a sufficient number have been deployed to support the desktops.
Domain controller promotion using backup tapes.
If you have a large domain with a massive Active Directory database, it can take a while to promote a domain controller across a slow Wide Area Network (WAN) link. This new feature permits using a copy of Active Directory restored from backup tape or backup file as the source for the initial build of the AD database on a newly promoted domain controller.
Windows Server 2003 makes roughly 400 changes to the base schema in Windows 2000. These changes must be in place prior to upgrading a Windows 2000 domain controller to Windows Server 2003. A new utility called ADPREP upgrades the schema and installs new attributes and containers in the Domain naming context to support the upgrade.
New domain operations.
A Windows Server 2003 forest can be restructured by changing the names of the domains and their parent/child relationships. You can also rename domain controllers within a domain, although you cannot move a domain controller between domains without first demoting it.