How do i fix a virtualized domain controller which won't boot when I've lost remote management connectivity to its host because the 'only' DC is down !!

Alan Bateman
Alan Bateman used Ask the Experts™
on
I have a single domain controller which runs in a virtual machine hosted by Hyper-V server 2019 which is a domain member but only runs server core i.e. command line and powershell. My dc is showing as started though I believe the boot is actually failing. I cannot get any further because I cannot connect Hyper-V manager to the Hyper-V server because domain connectivity is screwed up since my only DC is down - no DNS , no Active Directory, no authentication etc.. How can I fix the boot problem my dc is suffereing from when I do not have any access to it.  I WAS in the process of setting up a second dc on another physical machine as part of a migration to Server 2019.  Now I'm stuck.
Comment
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®

Commented:
RDP into the host and when it asks for a authentication, use the .\Administrator account for the login for local access.  

Example:

Login: .\Administrator
Password: [administrator password]
MaheshArchitect
Distinguished Expert 2018

Commented:
from Hyper-V manager, connect to affected hyper-v host with server local administrator and password and see if you get console 1st and then connect to DC console from hyper-v manager to find out further
If everything fails, then reboot Hyper-V host and then check if you get further
Olgierd UngehojerSenior Network Administrator

Commented:
You can try export this vm, download it to some local test environment and check what is going on. I do not recommend to join host to domain in single DC environment - probably is better to change it. Login as a local administrator.
JavaScript Best Practices

Save hours in development time and avoid common mistakes by learning the best practices to use for JavaScript.

Alan BatemanDirector

Author

Commented:
Sincere thanks for your help so far.  However, I am still struggling with this.  I can log into the Hyper-V server - either as a domain admin with cached credentials or as a local admin as \Administrator.  However, this just enables me to run cmd line and powershell.  I can start and stop mt DC VM using powershell VM-Start e.g. but my problem is that although it 'starts' it doesn't fully boot up and never becomes available on the network. this is why I am trying to access Hyper-V Server remotely with Hyper-V Manager and this is where I'm stuck. I am trying to Connect to Server and attempting to Connect with Credentials that work for RDC, but I get 'This computer is not configured to allow delegation of user credentials. Do you want to enable delegation? Yes/No'.  I have set up Group policy to enable delegation, I have tried adding registry entries, Replying YES to the above dialog box just loops and asks same question again - forever. replying NO gives another error dialog saying the WinRM client cannot process the request. A computer policy does not allow delegation of user credentials to the target computer. Sorry this is so long, but I still need help - unfortunately.  Thanks
Director
Commented:
Ok. After going up many blind alleys and suffering several false starts I have finally fixed this.  In the end I was able to connect to my Hyper-V server with Windows Admin Center (which I'd never used before). This enabled me to reconfigure the VM to ensure that it was booting from the correct volume (That was the first problem - I'd added a new virtual disk and it seemed to have taken priority in the boot order!) .  I also had to adjust the VM's  startup memory because the 'real' machine doesn't really have enough and the VM was failing with a memory problem. Once I'd fixed these problems my VM  booted correctly and finally I had a DC again and things looked a lot better. Once the Hyper-V server could see its DNS server again, the Hyper-V manager problem started to work again. So, if you can't use Hyper-V manager, try Windows Admin Center, it can be a lifesaver.
Thanks to all who provided help and advice.
MaheshArchitect
Distinguished Expert 2018

Commented:
Thanks Alan for detailed explanation and better solution

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial