Upgrading Windows NT domains, domain controllers, member servers, and standalone servers to Windows 2000 Server.
The actual upgrade procedures are almost identical to the procedures for installing fresh versions of Windows 2000 Server as described in install earlier in this chapter. Only additional issues are covered here.
Upgrading a domain means upgrading all the domain controllers in the domain. The important issues are:
Make sure your servers meet all the hardware requirements for upgrading to Windows 2000 Server. See install earlier in this chapter for more information.
Make sure you have your Windows 2000 domain structure planned out ahead of time. This includes determining the number of domains, domain trees, and forests you want to have in your new network. See domain, tree, and forest for more information.
Do the upgrade at night or on the weekend when user activity is low or zero.
Ensure that your domain controllers have fully replicated with each other prior to upgrading them.
Be sure to back up your domain controllers prior to upgrading them.
Disconnect one backup domain controller (BDC) from your network prior to upgrading the domain. This way you have a way of ensuring users can still log on should the upgrade of the domain fail or become problematic. If things really go wrong, you can then promote this BDC to the role of PDC and then recreate additional BDCs.
You must upgrade the primary domain controller (PDC) ...