Introduction
When you move to a new operating system such as Windows 2000, you have to make a crucial decision:
Reformat the machines and build from scratch; I have heard this strategy called 'Wipe and Roll'.
Decide on an 'In Place' upgrade to the Windows 2000. Simple, but no rollback, therefore impractical for big organisations.
With server migrations, introduce a new server into an existing network. Plan for a period of coexistence between NT 4.0 and Windows 2000 Active Directory.
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'In Place' versus 'Brand New Domain'
Broadly speaking, there are two strategies for a successful migrating to from NT 4.0 to Windows 2000.
1) The simplest strategy is the 'In Place' upgrade of NT 4.0. Just insert the Windows 2000 Server CD into your NT4.0 PDC and accept the defaults. Repeat this upgrade strategy for your BDCs. In my opinion, this 'In Place' method really only works for small networks with 2-50 users.
2) You may have good reason to create a brand new domain. For example you want your domain name to match your DNS name. Also you probably do not want all that old baggage in your new domain, so a brand new domain has great appeal.
There are two crucial considerations for a brand new Domain. Firstly get your naming conventions right before you install the first machine; make a mistake and you will have to start all over again. This is because you cannot rename a domain in Windows 2000. Secondly take steps to preserve your existing users.
Consider the following factors before you migrate
Hardware: New or existing machines?
Software: Which is the Right version of Windows 2000 for you? Plain, Advanced or Datacenter?
Clustering: Can you afford a multi-node installation? Consider linking to your SQL database servers in active / passive nodes with your Windows 2000 Domain controllers. If you like this clustering solution then review your plan and buy Advanced Server not Plain Windows 2000 server.
Which databases, configuration settings, do you need to preserve? Example: NT 4.0 SAM username database.
Budget, manpower, existing skills. Do you need to train or buy in Active Directory skills.