I basically just went through this... Make sure you do lots of planning. This shouldn't be a quick or lightly taken mission dude to the multitude of things that can go wrong.
Depending on the current domain name of your NT 4.0 network, you may be forced to change it. I was... this made things alot harder because I had 60 clients then that had to be added to the new domain... which also created new profiles on the w2k pro clients, so I had the daunting task of going to every client and moving profiles over and adding the system to the new domain.
I had 2 NT 4.0 servers running. A PDC (file & print server) and a BDC, Exchange 5.5 and MS-SQL 7.
Here is what I did in the run of Friday to Sunday Migration
Friday Morning, ran the defrag utility on the exchange 5.5 server databases to make sure the data I was going to migrate migrated cleanly. At 4:30 (when the office shutdown) I started swapping drives from my servers. Lucky for me I have 3 identical servers with hot-swap drives, and 2 new larger drives for a hardware upgrade at the same time.
Windows 2000 server is alot bigger than NT 4.0. Almost 1Gig for the operating system alone. Be sure you have enough space before you start.
I shut down the PDC and removed and installed new drives. (This way if something went wrong, switching cack to the NT 4.0 is much much easier). Installed Windows 2000 Server and set up the new domain and all the software and settings I needed including DNS and Service Packs. Then I installed the Active Directory Connector and Exchange 2000 and Service Pack 3 for Exchange. Meantime the Exchange 5.5 server was still running so I started the migration from the 5.5 to the new 2000. I had over 110,000 items to transfer and figured it would take approximately 6 hours to complete. So I went home and go some sleep.
Next morning I came in and found that the migration had stopped because I ran out of disk space. For some reason I made an 8 Gig partition instead of the required 80 Gig I planned on. So I scrapped it and started again. Oh ya, if the migration fails, and you run it again, it will duplicate all the messages calendar and contacts that were successfully migrated up until the error... Be sure to not let that happen, I'm still deleting duplicates.
Once I got the system all transfered, I also moved the MS-SQL 7 db to the MS-SQL 2000 db. This was alot smoother.
The nice thiong about the migration wizard is it will create an account on the new domain for every user that has a mailbox. Very Nice!.
Downed the NT 4.0 BDC and replaced the drives with my last 2 new drives and set up Windows 2000 service packs IIS and evrything I needed. Removed the drives from the other 2000 server and replaced the original NT 4.0 PDC drives and copied all the user data back over. Setup all the groups and permissions, shares.
This is a big job and shouldn't be jumped into. I did this migration this way so that I didn't loose any of the original data and could step back if things were going bad.
I suggest setting up a test network and install 2000 server a couple times and migrate data over to it from exchange a couple times before you actually go fo it.
I ended up working 127 hours in 8 days... brutally exhausted. Vacation will be nice.
send me an e-mail if you have any questions.
Tom Gignac
System Admin
*** Procrastination is like masterbation... feels great at first but in the end you are only screwing yourself***