In Part 3 here, I am going to look at upgrading my domain from Win08R2 to Win12. I shut all my test VMs off, snapped them, and then started them back up.
Now, there are likely a number of things to consider before doing an upgrade like this. I am sure I could go to <insert preferred search engine> and quickly find countless articles and blogs on this process. But, I figured I would just put the Win12 DVD in one of my DCs and run setup. Let’s see what happens.
So, setup runs, asks for a key, has me pick a version, runs a compatibility report… and STOPS! It looks like I need to run ADPREP before installing. Doing that now; running ADPREP /FORESTPREP
Failure. ADPREP could not verify that schema master has replicated AD to all DCs… or some such error. I used Sites and Services to replicate and tried again. SUCCESS! Running setup.exe again.
Fail! Need to run ADPREP /DOMAINPREP as well. (For some reason, I would have figured that these steps would have been more automated). Command was a success. Third time’s a charm?
Compatibility Check gives me a NEXT button, rather than a CLOSE button. Looking good. Installing. Rebooting. Getting ready. Another reboot.
Logging in, I see that DNS, DHCP, AD all look good. So, to update my functional level to Win12, I need to upgrade my second DC as well. Doing that now. Heh. No need to run ADPREP again… :/
Upgrade was successful. I tried updating the forest functional level, but it said that there were DCs in my domain that were not on the correct Windows version. Both DCs have been upgraded to Win12. Maybe server reboots will help?
Active Directory Domains and Trusts will not let me raise the forest or domain functional level. But, using the Active Directory Administrative Center lets me do it. Oops. Actually that failed too. It looks like this was a replication issue between the DCs again. Like before, I used AD Sites and Services to manually replicate between DCs. After replication, AD-D&T let me raise the functional level without a problem.
So, from this test, it looks like the basic steps are:
- From the Win12 disk on first DC
- run ADPREP /FORESTPREP
- run ADPREP /DOMAINPREP
- run setup.exe
- Check and make sure services are working
- From the Win12 disk on next DC
- run setup.exe
- repeat as necessary
- Make sure DCs have all replicated with each other and are all up-to-date with domain info
- Raise the forest/domain level to Win12
- Double-check everything
Of, course… you should make sure that you have good, usable backups of your domain/DCs. Also, as notes on the article listed below, you should probably run some checks to make sure there are no problems with your domain.