I am planning an upgrade to my server 2008 R2 to server 2012 r2 and wanted to check if my plan has a good chance of succeeding.

I have two DC's; DC1 is a server 2008 standard and holds all FSMO roles, DSN and DHCP ( it has no other significant functions). DC2 is a server 2008 r2 with DC, DSN roles along with some other important data applications.

I want to do an in place upgrade on DC2 to server 2012 r2 because 1) it is a very long and drawn out process to reinstall the applications and 2) the boss won't spring for a new machine right now.

I checked with the application vendors and they say I should not have any problems with an in place upgrade but I am not so sure about upgrading with the DC in place.

My question is an easy one: Would it be a good idea to just demote DC2, apply the upgrade and then promote it again?

Thanks in advance!

  • AFAIK,Microsoft does not recommend doing an in place upgrade, and definitely not for a DC. (In place upgrade may also inherit any niggling issues) I would suggest doing a clean install. I see you are apprehensive about the data applications, you should backup and document everything you can before you do it. – whizkid Jul 23 '16 at 0:43

I'm not sure why @whizkid thinks Microsoft doesn't recommend in-place upgrades. That might have been the case way back in the 2000/2003 era of Windows. But ever since the Win7/2008R2 generation of Windows, in-place upgrades have been pretty well supported. In fact, it has basically become the new default for desktop OSes. Just look in the tech news for all of the annoyed reports from people getting auto-upgraded from Win7/8/8.1 to Win10.

I've personally performed a decent number (10+) of in-place upgrades from 2008 R2 to 2012 R2 on domain controllers in production environments without any issues whatsoever (aside from the expected downtime during the upgrade process). Admittedly, most of those were running nothing but DC related services. But in any case, I wouldn't let the fact that the machine is DC stop you from attempting an in-place upgrade. But as always, have backups just in case.

| improve this answer | |
  • Thanks for your positive input. My in-place upgrade experience with Windows 7 and above workstations has been excellent. As this upgrade would introduce the first server 2012 DC in the forest, my thinking is that demoting it under server 2008 and then reinstalling under server 2012 would allow it to automatically apply any necessary forest prep tasks. In a round about way, I thought this would essentially mimic replacing the DC with a fresh install. I have complete backups of everything on the machine but reinstalling from backups takes a minimum of 12 hours just to get back to square one. – Rick H. Jul 23 '16 at 15:13
  • You can still do the forest/domain prep schema stuff in advance if you want. I usually do it just as an excuse to make sure replication is all happy before starting an upgrade like this. – Ryan Bolger Jul 24 '16 at 22:11
  • Update: Results of Upgrade - I decided to not demote the DC and went ahead and did the in-place upgrade. The process took about 2 hours with several reboots. The upgrade of the DC role was essentially uneventful. I did however have some issues with a few applications that had to be reinstalled to resolve some system security issues. One of my SQL databases was broken after the upgrade but I only had to repair the installation to fix it with no data restorations. All in all, while I would have preferred to do a fresh build on this server, the windows upgrade worked as good as can be expected. – Rick H. Aug 10 '16 at 14:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.