How to run Windows on top of Linux

Question

Just an idea for those of you who are using Linux but still need to run Windows XP or Vista for one reason or another.
When I bought my machine, I immediately reformatted the HD getting rid of Vista and all of that other prebundeled junk that made my system run like a sick 3-legged puppy. I then installed Debian Linux. The only thing that did not work was that silly "Winmodem" which I did not need anyway.
Now here's the really neat thing: I've run both Windows XP, Win 2K and other flavors of Linux as a "guest:" on top of my "host" Linux through Virtualbox which creates what's known as a virtual machine (VM) for the "guest" OS's (in my case Windows XP and 2k, and a couple of different versions of Linux). It works like a charm and it's free too!
The only problem is you can't play games through the VM, so you'll still have to dual-boot to Windows or use another machine for playing games. The same applies for any Windows application that requires hardware video acceleration. I can however play music through the VM and I can watch movies and run just about everything I still need that Linux does not yet provide (except for those stupid games, argh!). Supposedly there's a solution to the video acceleration problem, but it's not yet available for VBox and it's under heavy development so it's a new thing that may not work well.
One important note, for best VM performance you should make sure that you buy a CPU that supports either AMD-V or Intel-VT, but it'll still work without just slower (but still very acceptable) and you won't be able to run a 64-bit guest OS. Virtualbox will run under Windows, so you can do the reverse and run Linux through the VM on top of Windows, and you can also run any combination of supported "guest" OS's (eg, Linux on LInux and Windows on Windows is possible). It's great even for just experimenting with different system setups. For example, you can backup a whole virtual machine setup (it's only one file) and do tests that may irreversibly damage the Windows registry - if you completely break the system, no problem, you just restore from the back up and try again. This is a real big time saver for me.
There are alternatives to VBox, such as Xen, VMWare, KVM (requires amd-V or Intel-VT), and a few others. At this point I've only used VBox, so I can't say which is best, but VBox sure was easy to get up and running and it's been working great for me. 
Well that's my two-cents. Have fun with it.

Answer 1

garytr23 wrote:
One hint... don't try to use a disk image residing on an NTFS partition.  FUSE will take up lots of cpu time during writes and be uber slow.  
I was trying to share a win2k disk image between my Vista and Ubuntu install. 
Message Edited by garytr23 on 12-07-2008 10:55 PM
It works fine if the image is on a FAT32 partition but then you are limited to 4gb file size.
T60 2623-D7U, 3 GB Ram. Dual boot XP and Linux Mint.
T400 2765-T7U Windows 7
Registered Linux User #160145
FYI: I am not employed by Lenovo