I got a server from ewaste because the RAID card did fail and having SAS drives they couldn't even pull data from it with anything else. It was the domain controller and NAS so as you can imagine, very disruptive to the business. As they should they had an offsite backup of the system and so we just restored onto a gaming PC as a temporary solution until we moved them to M365 instead.
I just use software RAID on it now and so far so good for about 180 days.
This all happened two weeks before I started, so I don't know the exact details. If it was set up the way I think it was, I'd say yes, the DC was in it's own VM and then a separate VM would've been used as a NAS. Of course being hardware RAID the whole host server went down when that card failed.
They probably didn't have a second DC set up due to the DEFCON 5 levels of "We can't work!"
They were ultimately planning on going to the cloud anyway from what I heard and that catastrophe just accelerated that plan ahead