Vista - Running VPC from a VHD

I tried to be clever and I got most of the way, but I need some help for the
last leg.

I am trying to run a VM from a DVD by:
Creating a self-contained VM demoing our software

Compressing the heck out of it

Using an *.hta file to install VPC, copy the *.vmc file to a writable
directory

Using VBscript DOMXML to update the *.vmc file to point to the VHD running
on the drive.

The vhd is marked readonly

We use undo disks to store the changes (possibly a differencing vhd)

Here's where it gets interesting. It all works so long as its on a HDD.
This makes a lot of sense. I am sure I am violating the laws of physics and
good sense by trying to run it from a DVD (and storing changes on the host
HDD), but here's what happens when I burn it to a dvd.

The hta loads the *.vmc into VPC properly
The machine starts up without a hitch
Then it abruptly dies because of a Disk Read Error after the POST (inside
the VM).

This makes perfect sense to me. I am perfectly willing to accept this an
end game, "Stop trying to run it from a DVD, idiot" scenario. However, I am
curious. Is there some option I am missing? Some hidden VMC value I can
flip? Some bios magic?

Where is your swap file located, on the vhd thats read only?
Also where are your undo disks located?
--
David Vair
CNE,CNA,MCP,A+,N+


"Brian" <Brian@xxxxxx> wrote in message
news6A33465-C0B4-4EA0-9647-CB36E2BAC0EA@xxxxxx

On Thu, 31 Jul 2008 05:48:00 -0700, Brian
<Brian@xxxxxx> wrote:
You can't run an OS on a read-only volume, where is it going to write
to?
What you could do is use the VHD on the DVD as a parent drive and
create a differencing drive child on your local hard drive to save the
changes to.

--
Cheers,
Steve Jain, Virtual Machine MVP
http://vpc.essjae.com/
I do not work for Microsoft.

To answer David and Steve:

Well, you can run a readonly VHD. I successfully ran the OS using Undo
disks.

VPC is smart enough to store the undo disks in the run directory of the
*.vmc file. In this case, the %user profile%\my documents\My Virtual
Machines.

As for the swap file for the vhd, it's the default. Maybe that's the deal
breaker. I'm not sure how you change it (it would have to be configurable in
the *.vmc to work)

All I know is, you can successfully read-only VHD files (Recommended
practice with differencing vhds to keep your master clean). I suspect some
spooky nonsense with running from a DVD drive.

"Steve Jain" wrote:

On Thu, 31 Jul 2008 10:36:05 -0700, Brian
<Brian@xxxxxx> wrote:
Are you using Undo drives?

--
Cheers,
Steve Jain, Virtual Machine MVP
http://vpc.essjae.com/
I do not work for Microsoft.