I have a specific question. What happens, if I setup a streched cluster, and one of the sites AND the witness appliance dies? This question would also apply on a (yes I know, it is not supported) 2 Fault Domain setup? Can I still poweron a VM purely from the replica file, without having the active or the witness components to it? Thanks
That is correct, if both fail at the same time then quorum is lost, which means you can't power VMs on.
So with vSAN 7.3 there was an addition to allow a 2-Node cluster to survive if one of the nodes dies and connection to the witness also dies. I assume, that since a 2-Node cluster is essentially a stretched cluster that the same should hold true there as well, but not 100% sure.
but that would only work Tibmeister if there's some time between those two dying. As this new mechanism changes the votes and it needs to do this:
https://www.yellow-bricks.com/2022/03/17/stretched-cluster-witness-failure-resilience-in-vsan-7-0/
If both fail at the same time there's nothing you can do unfortunately.
Thanks Duncan! Does that really means, that in case one of the sites AND the witness node fails, I cannot poweron the VMs purely from the mirror objects?
That is correct, if both fail at the same time then quorum is lost, which means you can't power VMs on.