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This is because VM means two different things and has for a long time: IBM's VM was and is a hypervisor. It dates to the mid 1960s, in the form of CP-40, and i
by msla 3y ago
This is because VM means two different things and has for a long time:
IBM's VM was and is a hypervisor. It dates to the mid 1960s, in the form of CP-40, and it didn't run opcodes in software, but in hardware.
https://en.wikipedia.org/wiki/IBM_CP-40 https://en.wikipedia.org/wiki/IBM_CP-40
p-code machines, which interpret bytecode, date back almost as far, such as the O-code machine for BCPL.
https://en.wikipedia.org/wiki/BCPL https://en.wikipedia.org/wiki/BCPL
Getting people to distinguish between these concepts is probably a lost cause.
- Joker_vD 3y agoLooking at the IBM's tech from the sixties is somehow weirdly depressing: it's unbelievable how much of the architectural stuff they've invented already by the 1970.
- nine_k 3y agoNot depressing, but inspiring. So many great architectural ideas can be made accessible to millions of consumers, not limited to a few thousand megacorps.
- meepmorp 3y agoI remember seeing VMware for the first time and thinking that the PC world had finally entered the 1970s.
- cduzz 3y agoClose, but not quite -- you can't nest the VMs the way you can on "big iron"
- jlawer 3y agoI know Nested Virtualisation is a thing on both KVM and hyper-v, what is different about what you could do on "big iron"
- vetrom 3y agoA VM nest in "big iron" isn't a special case. It's a context push with comparatively exhaustively defined costs, side effects, and implications.
- cduzz 3y agoIn the early days of virtualization on PCs (things like OS/2's dos box) the VM was 100% a weird special case VM that wasn't even running the same mode (virtual 8086 vs 286 / 386 mode), and that second-class functionality continued through the earlier iterations of "modern" systems (vmware / kvm / xen). "PC" virtualization's getting closer to big iron virtualization, but likely will never quite get there. Also -- I was running virtual machines on a 5150 PC when it was a big fast machine -- the UCSD P System ran a p-code virtual machine to run p-code binaries which would run equally well on an apple 2. In theory.
- flenserboy 3y agoSo what might you say hasn't been brought in from the 80s yet?
- mr_toad 3y ago> Getting people to distinguish between these concepts is probably a lost cause. I think people here of all places should distinguish between these concepts. There are big performance and security implications of the two approaches.
- insanitybit 3y agoI don't think anyone has ever been confused because of the conflation of these two terms. The context typically makes it very clear.