It is possible to "virtualize" a OS who is already installed in the HDD?

Question

I want to make a dual-boot between openSUSE 13.2 and Windows 8, but the tricky thing is here: I want to boot one of the OSes while I'm using the other (doesn't matter the order).

Is that possible?

And if that config is possible, what are the minimum specs for that?

Answer 1

Yes. I've used VirtualBox to boot a usually dual-booted Linux system under my Windows install before now, and is actually reasonably simple:

1. Use vboxmanage internalcommands createrawvmdk -filename <output-file> -rawdisk <disk-device-name> -partitions <list-of-partitions-you-need> to create a .vmdk disk image. If running under windows, you can use the techniques described here to find a list of device names, and note that you'll need an elevated command prompt if you're running with UAC.
2. Set up a new VM and use "choose existing disk" to point it at the image you just created. If you're running under Windows, you'll need to run VirtualBox elevated to let it use the image. Note that is not able to run both elevated and unelevated under the same user account, so you may need to quit any existing instances first.
3. Let it boot, then install VM Additions.

Regarding minimum specs, it should work on any modern PC. To make it work nicely, though, I'd suggest making sure you have a lot of RAM (I'd probably aim for 16GB as a minimum).