[plug] Running Windows as an application on Linux?

[Russell Keith-Magee]

> Does anyone in PLUG have experience with this?  If so, what are
> your thoughts on the following:
>
> * is it really possible to have both Linux and Windows both
> operating on a one CPU machine at the
> same time (ie. not dual boot) and be able to have Linux & Windows
> apps running at the same time.

Yes. Both VMWare and Win4Lin allow the user to run Windows (or almost any
other major OS) in a virtual machine.

> * what Linux software or options are required to do that?   Where
> do you get them?

As above - VMWare and Win4Lin. Both proprietary software. There is a free
(beer/speech) option in Bochs; I haven't played with it, but all reports I
have heard say it is a lot slower, and still very much beta.

> * is it reasonably efficient to do this on a Pentium II or better
> grade processor with >= 64Meg of
> RAM?

The processor isn't really a problem; these VM's run executables pretty much
native on the processor, so you shouldn't observe a major slowdown with
respect to normal windows performance as a result of a processor bottleneck.
Of course, more grunt never hurts :-)

However, RAM is another issue. The VM's will use swap space in place of
physical RAM, but if you have 64MB of physical ram and your linux desktop is
using all of it (not uncommon for Gnome/KDE + mozilla), the VM will spend
lots of time thrashing to swap, which will dramatically slow performance.

The rule of thumb that I would advocate is to double up your physical
memory. If you like the performance of your windows box with 64MB of RAM,
buy 128MB for your doubled up VM machine. More the merrier.

> * Can it be done with any species in genus Gatesium or is it only
> possible with Win95/98?  Ie. can
> it be done to Win2K & WinXP?

AFAIK, yes. I've only played with NT and 95, but the install options allow
you to select all sorts of (bad pun alert) window pains, plus all sorts of
BSD's, or even Linux. OS/2, BeOS and AtheOS had some problems last time I
tried.

> * any caveats or warnings about attempting this other than the
> obvious "why do you want to run
> Windows at all"?

There are a few caveats, mostly with respect to hardware support. The most
noticeable of these is graphics support.

VMware, for example, sets up a virtual SVGA monitor, which can be displayed
full screen or in a window under X. However, this driver will not make any
use of any hardware acceleration you may have (eg, you can't install the
NVidia drivers under VMWare to support your spanking new GeForce4). As a
result, game support ranges from poor to none. If a game does work, expect
to get VERY low framerates in your favourite gib-splattering game.

Analogous problems exist with any other hardware; I managed to sort of get
my vendor provided scanner drivers to work under VMware, but they tended to
be a little flaky, and they required lots of messing about with the Linux
install to allow the VM access to the hardware.

HTH
Russ %-)