I'm assuming this is a lot like VMWare, or the like?<br><br><div><span class="gmail_quote">On 8/24/05, <b class="gmail_sendername">John Esak</b> <<a href="mailto:john@valar.com">john@valar.com</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
> > Okay, I'm going to assume I'm only talking to people who care.<br>> :-) Rick did<br>> > the coolest thing for me recently. He set up virtual pc for me<br>> on my 2003<br>><br>> My question is this: Is the Virtual PC card-based (like the old PC board
<br>> for Macs, and the X-Box devsys board for PC's) or sofware-only?<br>><br><br>It is just software.</blockquote><div><br>
Assuming its something like VMWare, then yes. The problem with that
system is.... It is sharing all system resources with the host system.
Its like running Unix with all the headroom of windows bogging down the
system - in addition to the virtual guest OS. Furthermore, running a
host system of windows means you lose the stability of the the guest
system. For me, this is an issue - I run *nix servers (not SCO - I tend
towards a mix of linux and bsd variants - but it's all the same in
regards to this) for the stability - for knowing that a software update
or even a simple network setting change will never require me to
restart the system. For knowing that it is less susceptable to virii,
that a runaway process stands a slim-to-none chance of crashing my box.
For the security inherent in the *nix based systems. Running in a
virtual machine, you give all that up.<br>
</div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">> Assuming software-only, is it actually running the entire system, or is it<br>
> running the binaries under emulation.<br><br>Currently, it is a black art to me. I have no idea how in the hell it can<br>run all the things SCO has going for it, when it is just ONE file on the<br>system! You'd think a zillion binaries would have to be running all the
<br>time... extracted from this file as needed. Unbelievable.</blockquote><div><br>
<br>
Essentially (again, assuming this is something like the virtual machine
systems I have experience with) the data file(s) represent partitions
for the virtual machine. The VM software emulates a virtual bios/etc,
and provides access to input/output devices as required. It only
appears to windows as one running process, although typically it will
also install some network drivers, which give the guest OS access to
network devices (which can, in typical situations, be configured in
several different ways. One would be to see the host OS as a gateway,
meaning the virtual machine is essentually nat'ed behind a gateway on
the host OS. It can also be configured to have separate access to the
network adaptor, essentially letting it appear to the network as its
own system.<br>
</div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">><br>> Assuming it's running the entire system, how's the speed? It's still
<br>> through some sort of emulation, so what does the performance loss "feel"<br>> like. I'm not one of the performance extremists that demands a picosecond<br>> benchmark set--I just want to know if it "feels" 95%, 75%, 50%,
<br>> whatever...<br><br>It runs as fast or faster than any SCO system I have ever seen. There is<br>zero performance problem. It just goes as fast as I have ever seen things<br>go. I did an Edge backup through ftp to my old SCO box across the 10/100
<br>network and this took WAY more time than a regular backup to tape, but I<br>would expect it to... I'll be getting a fast tape drive for the system<br>soson. I decided to put the jukebox somewhere at Nexus.</blockquote>
<div><br>
Performance isn't typically dog slow, but remember - you are running
your virtual OS on hardware shared with a windows installation. There
*will* be a significant load on the resources of your virtual machine,
and a virtual machine in the scenario we're discussing will *always*
run slower than a native installation on the same hardware.<br>
</div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">><br>> Given all that, can I assume it would run Linux just as easily?<br>
><br>Without any doubt. I think Rick runs some Linux or another... SuSe I think<br>on his box in this way.</blockquote><div><br>
Thats correct. Most Virtual Machine applications can support almost any
guest OS - windows, linux, bsd, SCO, Sloraris, bob's random OS -
you get the picture. <br>
</div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">> > old SCO system there. I can now lose one entire machine, one<br>> keyboard, one
<br>> > source of noise and heat, one system that needs backing up<br>> every night. I<br>> > save the space and the noise, but there are so many benefits besides. It<br>><br>> I collect old systems. :) J/K
<br>><br><br>Remember that fork, Mark. You're done... :-)<br><br><br>> Now the question I have is, how much access does it give you to Windows<br>> while it runs the virtual system? Can you minimise the Virtual PC to
<br>> systray and let it run as a service unless you otherwise need to<br>> access it,<br><br>Yes, goes minimized and keeps on ticking without any problems. And I'm<br>experimenting with the access both ways. It allows you to assign the
<br>devices, say F: to be the DVD-R and it accesses the physical floppy, etc.<br>You can arrange the mouse to work on both systems in the same way... I think<br>there is a clipboard too!</blockquote><div><br>
Different virtual machines (there are many - VMWare and the open source
bochs are the two I know best, but there are tons out there) support
different forms of minimization - minimize to systray is likely an
option, and I would imagine that one of them must support running as a
straight service on windows.<br>
</div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">> or does it commandeer the entire system? I wouldn't say it'd be pointless<br>
> to not be able to, as it'd be handy to just fire up linux for some things<br>> and not have to reboot all the time. However, if you get access to both,<br>> how's the priority sharing feel?<br><br>There is an elaborate Settings menu that lets you assign how much priority
<br>you want the virtual system to have vs. the host system. Lots, not much, a<br>reasonable default blend...all the way to shutting down the priority of<br>either system to almost nothing...<br><br>> Got a URL for this thing? It does sound cool. Tell me it'd work under
<br>> Windows 2000 Pro, not just 2003 or XP-SP2. :)<br>><br>> mark-><br><br>Will post a URL later... once I find one. :-) Unfortunately, it requires at<br>least 2000 server, not 2000 pro. Sorry. I believe it took getting SCO 6 to
<br>make it work... but I think most any Linux would work without hassle.<br><br>John</blockquote><div><br>
There are many virtual machine systems out there. Google would likely
turn up any number of useful results. Additionally, there are many
versions of this sort of software that run on differnt host systems - I
run virtual machines with linux as the host system, and windows as the
guest OS. This allows me a good place to test questionable
applications, see the effects of a virus in an easily rolled back
sandbox, and have several versions of windows at my fingertips. For
some of my users running linux day-to-day, it gives them access to what
limited windows applications I have to support that I can't get to run
under Wine or the like - and also means that they can't cause problems
that users are prone to causing on windows (at least, my users are
prone to causing problems) because a rollback is only a click away..<br>
</div>Bear in mind, there are also interesting ways of
virtualizing system resources that involve signicantly less system load
- the linux virtual server project (<a href="http://www.linuxvirtualserver.org/">http://www.linuxvirtualserver.org/</a>)
is a good example. These offer less flexibility (typically, you are
restricted to virtual copies of the same OS) but they vastly reduce the
overhead of running guest systems, and still offer an excellent way to
run applications in a sandbox, without having to grant the
application(s) any access to the host system. Kind of like running an
entire OS in a chroot jail.<br>
</div><br>
Virtual machines are useful - but personally, I would never willingly
nor happily run a production server in a standard virtual machine in
the configuration you mention - in large part because of the concerns
with making a more secure/stable *nix susceptable to the foibles and
frailities of the windows host system. I've considered the linux
virtual server style of applications for some things, but ultimately
couldn't convince myself that the security gain was worth the
performance hit - or I find a more elegant way to gain the security I
was hoping to buy.<br>
<br>
-- Silas<br>
<br>