[Beowulf] Virtualization in head node ?

Robert G. Brown rgb at phy.duke.edu
Wed Sep 16 15:12:52 PDT 2009

On Wed, 16 Sep 2009, Stuart Barkley wrote:

> On Wed, 16 Sep 2009 at 12:01 -0000, Robert G. Brown wrote:
>> XPPro will run forever on the virtualized hardware interface as long
>> as I can get linux to boot and run devices on the toplevel system.
>> If I change machines, my XPPro VM can go with me without all of the
>> tedious crap from Windows Update and phone calls to Windows service
>> people that don't know what you're talking about or what to do about
>> it once they do.
> Are you sure about this?  We have some interest in being able to
> archive complete installations for future use (e.g. +5-10 years).
> I'm skeptical of the existing trend of virtualization to handle all of
> the needs for product activation or other software licensing schemes.

Obviously, I have no idea.  How could I?  But it is plausible that it
would work over a 10 year frame.  There is really very, very little
reason to change the virtualized hardware interface; it is usually
chosen to be a wrapper that simulates something with boring, common,
simple drivers OR it is a passthru.  Passthru's obviously won't usually
work -- if you had an OS from a decade ago that didn't know about USB,
I'd guess that the USB drivers would either not work or would actively
break it.  OTOH, you can deconfigure USB passthru.  I'd say that there
is an excellent chance of running VMs for a 5+ year time frame,
decreasing out to 10 but still quite possible at 10, especially for
"vanilla" VMs that e.g. just use VGA, a basic network, and nothing else.

You're obviously at serious risk of the CPU itself going away at the ten
year mark.  Who knows if even 32 bit emulation will exist in a decade,
or if even 64 bit emulation will still exist?  Who knows if the
instruction set will have changed?  Getting something that downshift
emulates a 32 bit intel CPU on a 128 bit 16 core 2020 CPU with an
entirely new instruction set... well, that might be a problem.

> The following is speculation not facts.
> If you move an existing VM within the same virtualization and cpu
> technology you may be able to get away without reactivation or
> obtaining a new license key.  MAC addresses can be set in several
> virtual environment which can help in some cases.

Usually this is the case, and often it is even legal, if you don't run
two copies of one VM at once -- VMs are a good way to get failover and
generally are viewed as a reinstall of a system from backup on new
hardware, which is usually permitted or at least tolerated by any
company in the server business.  MS gets pissy IIRC about virtualizing
Vista or better versions of Windows -- I think you have to have at least
a business or professional class Vista license before it is legal to
virtualize it.  Of course this is shooting themselves in the foot,
because it means that people trash Vista Home and install XPPro as a VM
instead, stretching out that support lifetime still more.  In a VM
nobody cares -- if you boot a frozen VM image and mount space from
elsewhere from data, even if they REMOVE all support and update streams
you can't credibly get a virus on it.

> However, a lot of other things can impact product activation and
> licensing checks.  Different virtual environments provide different
> emulated devices.  Emulated disk serial numbers, BIOS versions, cpu
> family, cpu stepping, processor flags and other unknown things may be
> included in the product activation or licensing checks.
> It may be that some of the processor emulation technologies can
> provide this functionality.  qemu can emulate a number of hardware
> systems but again only in specific configurations which may differ
> from a real world licensed configuration.

Yeah, I don't really view it as a way of bypassing licensing, and in my
case since Duke has a site license for Windows as well cloning an XPPro
VM is totally legal for me.  I did it yesterday -- it was awesome.  A
straight copy of the VM over, boot it on the new system AND on the old
system, there it is right down to my (cough cough) copy of DII
expansion.  Which, um, I don't plan to play on more than one VM at a


> Stuart
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Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu

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