Server is not a cluster warning

[jesse@TLC]

We ran into an issue recently, were we started receiving "Server is not a cluster" warning on random windows clusters running on our Hyper-V environment.
When checking on the protection groups, I noticed that Cluster Hosts where being skipped, and if the option "All Computers that have been offline for over 30 days" was unchecked, things went back to normal.

I opened a call with support and they identified that the issue was being caused by the domain controller the protection groups were pointed too, pointed to another DC and the issue was fixed.

My Question is, How is Veeam determining that the VM has been offline for more than 30days?

[david.domask]

Hi jesse@TLC, welcome to the forums.

Per the User Guide page on this option:

All computers that have been offline for over 30 days — all computers in the domain that have not logged on to Active Directory for more than 30 days.

So likely it was seen that the servers had not logged in (accessed) Active Directory for more than 30 days. So would make sense if these servers were having issues reaching the Domain Controller that this option would be followed.