About virtual machines

[Battousai001]

Hi, I just learned about virtualization, virtual pc and virtual machines and tried one out. I get to know about VM's after asking about running different O.S. in one machine.

I was fascinated when I tried microsoft's virtual pc 2007 and ran win99se on it. I was quite amazed on the technology as you can run multiple o.s. on top of another o.s., anyway, the reason why i got stumbled upon vm's is because i needed to run win98se again to run a game which cant run on xp. At first my idea was to put two o.s. on my machine by putting up partitions, but somebody suggested to try a virtual machine, so i made a little research and tried one out.

I have some couple of questions about virtual pc's and virtual machines:

I noticed that virtual pc makes up a virtual hard disk that can be bigger than your actual hard disk but the actual limit is your real hard disk right because the virtual hard disk size gets bigger when data is being added right?

One of my biggest concern is that in virtual pc, you cant use your real graphics card so the games you will be playing within the virtual machine cannot use your real graphics card, only the virtual graphics card made by the virtual machine is this correct? Is there a virtual machine that let you use your real hardware like graphics card?

and regarding the speed of virtual machines, i find the speed of win98se on the virtual machine a bit slow even if you allocate a lot of memory for it, is there any way to speed this to near native speed (the "run virtual machine at full speed" is already checked by default), or is there any other virtual machines that can run faster than virtual pc?

Lastly, VM's VMPlayer is freeware but I cant make a virtual machine on it and I cant run microsoft's virtual machines in it, does it mean there is a need to purchase another program that lets you make a virtual machine with VMware?

 

[Brazen]

You can create and run virtual machines with VMWare Server for free. I have not used VMWare Player so I don't know what the advantages/disadvantages are between Player and Server.

There is no way to use your physical graphics card within a virtual machine. It is not technologically possible. Older games likely will not have a problem with this though. You would just have to try it and see.

The only advantage to creating a virtual harddisk bigger than how much free space you have is if you ever plan on moving it to a bigger physical harddrive. I image Very Bad Things (tm) will happen when your physical harddrive fills up but your virtual harddrive thinks it has more room.

 

[Robor]

FYI -- VMWare Server is also a free program. A coworker of mine is running a VirtualBox of Vista from within a Ubuntu Gutsy (7.10) host with good success as well.

 

[accguy9009]

As Robor suggested try Virtual Box. Unlike Virtual PC you can use XP Home as host.

 

[Nothinman]

One of my biggest concern is that in virtual pc, you cant use your real graphics card so the games you will be playing within the virtual machine cannot use your real graphics card, only the virtual graphics card made by the virtual machine is this correct? Is there a virtual machine that let you use your real hardware like graphics card?

No, that's impossible. But VMWare and Parallels are working on releases that support hardware accelleration so that you can use 3D apps in the VM, I have no idea if MS is making that a priority in VPC yet or not.

 

[ShawnD1]

Originally posted by: Battousai001i needed to run win98se again to run a game which cant run on xp.

Just curious, but what game is it? A few of my games wouldn't work on XP unless the installer was run in compatibility mode.

 

[Battousai001]

Originally posted by: ShawnD1

Originally posted by: Battousai001i needed to run win98se again to run a game which cant run on xp.

Just curious, but what game is it? A few of my games wouldn't work on XP unless the installer was run in compatibility mode.

Actually its two games, Final Fantasy VII and Metal Gear Soid Integral. In Final Fantasy VII the compatibility mode feature doesnt work, but in Metal Gear it does but still there are some little bugs.

I was now as interested in Virtual Machines as playing the games as I was a bit amazed with the technology. My only concern is why cant virtual machines use the real graphics cards and make up a virtual graphics card instead? is it technologically challenging?

From what I experience from usage and my plain knowledge, VM's are programs that creates a "virtual hardware/pc" so that another operating system can be installed within it. so the program basically makes up a "not real" hardware. Does this include the processor? I was thinking that makers of VM's can't virtualize high-end hardware as VM's depends on the real hardware.

 

[Nothinman]

My only concern is why cant virtual machines use the real graphics cards and make up a virtual graphics card instead? is it technologically challenging?

If you can come up with a way for 2 drivers to manage the same hardware without any mediation you'll be set for life.

Does this include the processor? I was thinking that makers of VM's can't virtualize high-end hardware as VM's depends on the real hardware.

Not really, the instruction sets are the same and most of the CPU instructions are just passed along untouched. A few instructions need to be trapped and changed but they only do that when absolutely necessary for performance reasons. VM makers can virtualize whatever hardware they want, but they have to implement a software version of that hardware so they tend to choose things that are fairly simple and common so that they don't have to do much with drivers.

 

[ShawnD1]

Originally posted by: Nothinman

My only concern is why cant virtual machines use the real graphics cards and make up a virtual graphics card instead? is it technologically challenging?

If you can come up with a way for 2 drivers to manage the same hardware without any mediation you'll be set for life.

Actually this is already true, somewhat. Part of DirectX10 is that Vista virtualizes the video hardware for each program making a video request, so each program thinks its the only one running. In theory, VMWare could let the virtual machine make direct calls to Windows Vista to get video rendering. It would be just like playing movie or game, but instead of 1 layer of virtualization (Vista), it would go through 2 layers (Vista and VMWare).

 

[Nothinman]

Actually this is already true, somewhat. Part of DirectX10 is that Vista virtualizes the video hardware for each program making a video request, so each program thinks its the only one running. In theory, VMWare could let the virtual machine make direct calls to Windows Vista to get video rendering. It would be just like playing movie or game, but instead of 1 layer of virtualization (Vista), it would go through 2 layers (Vista and VMWare).

That's at the API layer, not the driver layer. Any application (in this case VMWare) still has to use that particular API and let the host system's driver handle the hardware.