The VM-software (VMWare, VirtualPC, XenSource or any other) is used to run an image for your virtual environment. You can either create such an image yourself, by installing an OS on a blank virtual machine (with VMWare server for instance) or download a pre-installed one (there are plenty Ubuntu images out there for instance).
The system requirements for running a virtual machine are not as high as those for emulation. DosBOX really needs a pretty powerful machine because it actually emulatos a processor, a soundcard etc. (i.e. an entire computer). There's a guideline that a system can only be adequately emulated by another system that's thrice (3 times) as powerfull in terms of processing power and memory.
For virtualization this is not the case. Usually there virtual machine gobbles a large chunk of memory (which is used as RAM for the VM). The more mem your PC has, the more you can allocate for the VM. There's always overhead (for your 'real' OS and the VM software need to run somewhere as well), so if you got 1 GB of memory you can probably allocate as much as 750 mb's or something for the virtual PC. The virtualization software then does NOT emulate all the hardware, it simply relays all the requests to the real hardware in your PC (such as processor, soundcard, NIC etc.). This takes a little bit of time and effort, so the VM doesn't run as fast as the real thing. My experience is that the VM runs about 30-40% slower then your actual PC.
For storage, the VM uses a local filesystem. All things you install while running the VM end up getting into the Image-file. That way it doesn't really matter whether the underlying machine uses a FAT, NTFS, EXT2, EXT3 or whatever filesystem. The VM uses a local one which can be any of those (or something completely different). So, if you run a VM with Win XP, you get a local registry, and the older games get insalled within the virutal filesystem. The same goes for Linux. If you set up your partitions to use, say ReiserFS, your underlying XP environment won't notice anything. Usually you can read-access the FS of the underlying system as well (at least Linux can READ NTFS and some Kernels allow Write access as well).
You need an OS to run the VM software one. There's VMWare for both Linux and WindowsXP, so you could choose either platform. Most people who want to give Linux a try, run the VM software on a Windows box.
As for your last question: Ubuntu works with almost any graphic chip out there, on-board or not. All Ubuntu installs I've performed auto-detected my graphics chipset out-of-the-box, so I wouldn't worry about that too much!
Hope this answers your question!
|