My Domain Controller is unavailable (Windows Server 2012 R2). What to do?

Question

Hi everyone,

One of my Domain Controllers "died". I had to reboot it, but it doesn't work, and it crashed. So, I have a backup made last week (this DC is a VM). What should I do?

1- Use this Backup? If so, how to initialize the DC? Should I initialize this DC by using an authoritative restoration? How to make this?
2- Making a MetaData Cleanup of the unavailable Domain Controller and then creating a new DC from the scratch?

Thank you.

Answer 1

How many domain controllers? Assuming there's another healthy one the simplest solution is to seize roles (if necessary)
https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/transfer-or-seize-fsmo-roles-in-ad-ds

then perform cleanup to remove the failed one.
https://learn.microsoft.com/en-us/windows-server/identity/ad-ds/deploy/ad-ds-metadata-cleanup
https://techcommunity.microsoft.com/t5/itops-talk-blog/step-by-step-manually-removing-a-domain-controller-server/ba-p/280564

then rebuild the failed one.

I'd use dcdiag / repadmin tools to verify health correcting all errors found before starting any operations. Then stand up the new 2019, patch it fully, license it, join existing domain, add active directory domain services, promote it also making it a GC (recommended), transfer FSMO roles over (optional), transfer pdc emulator role (optional), use dcdiag / repadmin tools to again verify health.

--please don't forget to upvote and Accept as answer if the reply is helpful--

Answer 2

Any progress or updates?

Answer 3

Hi，

Welcome to share here!
If the "died" DC is not the only on your domain, we don't need to restore it from the backup.
For a FSMO holder, we may try to size the FSMO role from a good DC.
Then perform a metadata cleanup.

If you still want to it a DC again, you can create a new one as you mentioned above.

If you have any questions about it, feel free to let us know.
Best Regards,

Answer 4

Just checking if there's any progress or updates?

--please don't forget to upvote and Accept as answer if the reply is helpful--