Server down this morning...
VHDX File is just gone... It's missing...
I found out that Windows Defender had detected it was (or had) a virus and quarantined it...
How Windows defender even would ever quarantine a VHDX is beyond me.
Come on Microsoft!
That's odd. VHD/VHDX files are NOT ever scanned by the host, unless of course they are mounted in the same way as a disk or USB disk is to the host OS for example. Otherwise, they are treated like a black box. So something else had to have happened for it to be quarantined by the host OS. That doesn't just happen willy-nilly.
Additionally, VM files are automatically excluded when the Hyper-V server role is installed. So again, something isn't configured correctly or something weird is going on.
What happened to you isn't default behavior.
Not sure, we 'inherited' the server. We don't do HYPER-V any longer. Everything is KVM now. (Proxmox)
But it was for sure quarantiined. Funny thing is that Windows defender scan of the actual VM shows no virus... So weird.
My guess would be that the VM's AV cleaned it up separate from the host's AV killing the VM.
@Oksana KVM really should be part of the converstaion.
Right? Hyper-V and VMware are the two I'd rule out, period. The short list is KVM and Xen. Hyper-V is effectivley discontinued. Vmware is the worst product in the field (and the most expensive, but even at free, it's the worst offering out there.)