[Info-vax] VMWARE/ESXi Linux

[Dan Cross]

In article <vinctl$3sjq$1 at dont-email.me>,
Arne Vajhøj  <arne at vajhoej.dk> wrote:
>On 12/3/2024 11:10 AM, Dan Cross wrote:
>> In article <vina48$3sjr$6 at dont-email.me>,
>> Arne Vajhøj  <arne at vajhoej.dk> wrote:
>>> On 12/3/2024 10:36 AM, Dan Cross wrote:
>>>> In article <vin68p$3sjr$4 at dont-email.me>,
>>>> Arne Vajhøj  <arne at vajhoej.dk> wrote:
>>>>> KVM runs in Linux not on Linux. Which makes it type 1.
>>>>
>>>> Nope.  KVM is dependent on Linux at this point.  The claim that
>>>> it is a type-1 hypervisor is predicated on the idea that it was
>>>> separable from Linux, but I don't think anyone believes that
>>>> anymore.
>>>
>>> It is the opposite. KVM is type 1 not because it is separable
>>>from Linux but because it is inseparable from Linux.
>> 
>> Kinda.  The claim is that KVM turns Linux+KVM into a type-1
>> hypervisor; that is, the entire combination becomes a the HV.
>> That's sort of a silly distinction, though, since the real
>> differentiator, defined by Goldberg, is whether or not the VMM
>> makes use of existing system services, which KVM very much does.
>
>ESXi is basic OS functionality and virtualization services
>in a single kernel.

Yes, but it doesn't do much other than run VMs and support those
VMs.

>Linux+KVM is basic OS functionality and virtualization services
>in a single kernel.

Yes, but it does much more than just run VMs.  For example, I
could run, say, an instance of an RDBMS on the same host as I
run a VM.  Linux, as a kernel, is separable from KVM; KVM, as
a module, is not seperable from Linux.

>They are logical working the same way.

Funny how this is the inverse of what you tried to argument
in https://groups.google.com/g/comp.os.vms/c/nPYz56qulqg/m/LN-xzlJ1AwAJ,
where you wrote:

>The differences are not in how they work, but in history
>and reusability in other contexts:
>* Linux existed before KVM
>* Linux has more functionality so it can be and is used without KVM

Yes, and that's the distinction Goldberg defined.

>But type 1 vs type 2 should depend on how it works not on
>history and reusability in other contexts.

Like I said, the terminology is imprecise.

	- Dan C.