Building a New Active Directory and moving from Old Domain

I am in the midst of building a new Active Directory 2008 Domain. My organization is currently running on a AD2000 and the decision has been made to build a new AD instead of migrate our current AD to 2008 ADDS. We have an Exchange 2003 infrastructure and Team Foundation/Sharepoint server that are in the 2000 AD environment. I know the easiest route is to migrate up but the current AD was not built correctly and is having problems. For this reason the powers that be decided to build a new AD.

I know ADMT is one tool that I will need for this project but what other tools, resources, and books/articles can you suggest for such a project especially for moving Exchange from the old Domain to the New?

I'd encourage you to re-think the whole "rebuild" idea. There's nothing in the current AD domain that can't be "fixed" by migrating and cleaning it up.

If your decide that you have to rebuild it, you're going to need to do a PST migration of Exchange (since you're running on Exchange 2003 and can't do a cross-forest mailbox move).

Basically, this involves using ExMerge to export all the contents of the original Exchange Information Store to PST files. After you've created the new AD and new user accounts (either using ADMT or "by hand"), you'll import those PSTs back into the new Exchange IS. Finally, you'll need to use something like ADSIEDIT or a script to add an X500 address proxy to each user account that matches the "legacyExchangeDN" attribute that was assigned to their user accounts in the old domain to insure that replies to imported emails function properly (see http://blogs.technet.com/sbs/archive/2009/05/21/cannot-reply-to-old-emails-or-modify-old-calendar-items-after-pst-mail-migration.aspx for details).

Again: Re-think doing this "rebuild" versus migration. Acouple of hours with a competent AD consultant would be all you'd need to idenfity the problems in the current domain and plan for "fixes" as you upgrade to W2K8. You wouldn't need to go thru any of these gyrations with your email and you'll end up spending less time and money for what amounts to a cleaner, better solution.

It's an interesting approach; I wonder if the powers that be are aware of how much work and hassle will be involved in this. Then again, depending on how badly broken it is, and the size of your user base (which I gather from your previous post is rather small) it may well be the right way. If it was me I would definitely be looking to exhaust all possible alternatives before definitely committing to the new build, however.

I gather from your previous post that you have a multi-forest environment, so an alternative option would be to just migrate the users, computers, services, etc from the other forests back into a single central domain. Even just dropping and setting these up from scratch would be a hell of a lot less hassle than recreating everything from scratch.

Then again, as you said, the powers that be have made the decision, so there might not be anything at all you can do to change this.

For Exchange the only really sensible migration method for you is to use exmerge to dump out your mailboxes to PSTs, then import them back in, either via Outlook import or exmerge again. Be aware however that you'll lose single-instance storage by doing this, but also be aware that losing single-instance storage may not be that big a deal.

There are also limits with exmerge; I haven't seen more recent versions but the last time I used it (Ex 2003) it didn't support Unicode PST exports, meaning that there is a 2GB PST size limit. Other practical considerations such as loss of SIS and general PST overhead may mean that for any mailbox over 1 GB you'll need to export from Outlook.