the way i understand it hibernating an OS dumps ram to a file and powers off, so could it be possible to run two OSs “simultaneously” by alternating between hibernations?
They sold laptops with this feature at one time. https://www.youtube.com/watch?v=q5M0TwnkWUM&list=PLec1d3OBbZ8IBeFODHXLy0m0okuZhqJnT
This entire series by Cathode Ray Dude is a wonderful dive into the world of PC boot sequence, for the folks interested in a touch of embedded architecture. His delivery is also on-point, given the complexity and obscurity of the topics.
From this video alone (41:15):
The way this worked was: they installed Xen hypervisor on your PC, put Hyperspace in a VM and Windows in another. Now, you either know what a VM is – and I don’t need to explain why this is terrifying – or you don’t and I need to make you understand so you never independently invent this.
And (43:59):
This is just a bad idea, ok? Virtualization belongs in data centers. Putting some poor bastard’s whole OS in a VM is a prank. It’s some Truman Show shit. It’s disassembling the coach’s car and putting it back together inside the gym. It’s not remotely worth the trouble and it probably didn’t work.
