On 2021-12-10, at 15:04:59, Massimo S. wrote:

Il 09/12/2021 21:16, Doug Bissett ha scritto:

On 2021-12-09, at 20:20:28, Massimo S. wrote:

Hi all,

is it possible to give 3 or 5 cores to an AOS503 guest VM?

thanks

massimo

Yes.  AFAIK, you can use up to the number of real cores. HOWEVER, using more than one core will cause problems,

why?
never had one with ACPI
my production servers use 1, 2 or 4 cores, i never had one hang or trap

and it will likely not make much difference in performance (it makes very little difference when running a XP, or win 7,

guests).

no, sorry, they do if you are using real world production servers

>From what I see, VBox uses support similar to Hyper Threading, and Hyper Threading is not very friendly to OS/2.
Try it, and see what happens. I suspect that it will hang after a short period. I haven't tried it for a couple of years, something

may have changed (but I doubt it).

my production servers use 1, 2 or 4 cores, i never had a trap or hang or whatever
my only doubt was MP (3,5,7) not SMP number of cores

you didn't try that
ok, thanks anyway

massimo

I think you misunderstood. The VBox HOST can run under any number of cores (including Hyper Threading). Using the setting in VBox to use more than one core for an OS/2 GUEST will cause trouble because VBox seems to use the same thing that Hyper Threading uses. Hyper Threading is not completely compatible with the OS/2 job scheduler, and it will, cause OS/2 to hang, eventually (usually sooner, than later).

My comments about XP and 7, were about using multiple processors in the GUEST. It makes very little difference over running them with a single processor configured, but that may depend on exactly what you are doing with them.