Virtualization question

Five_Star · 20 Mar 2009 at 07:56

On a virtualised system the system is arranged in layers as below, hardware, VM software, VM guests, applications.

Applications
VM guests
VM software
Hardware

When the hardware is booted up you usually get access to a simple interface provided by the VM software. This software has direct access to the physical hardware on the machine. The VM guest machines must be controlled via remote desktop or other VM access system.

Is it possible to have one of the VM guest machines gain access to the physical hardware so that when the machine and VMs start up somebody could work at the machine locally on one of the VM guest as if it was on the physical hardware in front of them?

iaind · 20 Mar 2009 at 08:35

Easy answer to this one - No.

I'm going to assume you're talking about VMware ESX here. The "OS" you see on the console doesnt actually have direct access to the hardware, its actually a Linux based virtual machine. You can see the Linux bootstrap handing control to the hypervisor at the stage of the boot that says "starting scheduling...". The hypervisor is the only part of the system that has direct control of the hardware.

If you don't believe me - some people refuse to believe that what they see on the console is a VM - just log in and run the linux "top" command and see what memory you've got....

The service console should provide enough functionality to enable you to get back into the VI client if the management and watchdog services fail, but I would exercise caution when restarting services and using the vmware-cmd/vmkfstools if you dont know what you're doing.

Generally speaking, this should never be necessary, provided the management service (vmware-mgmt) is running you'll be able to access everything from the VI client or a web browser. If that service fails, the watchdog service exists for the sole purpose to spot it failing and restart it.

Hope this makes sense!

Five_Star · 20 Mar 2009 at 08:59

Thanks for the quick reply. I've (we've) never used VMware, only Microsoft Hyper-V and I know that I can't do what I want with that.

It's a shame because we have an ideal place to use a VM server to display presentations on a LCD and we have nowhere to place another PC to power the presentations but the server is behind a partition wall so it's easy to run the monitor cable to the screen and wanted to start a 'default' VM guest to run the presentations.

I wonder if it will ever be possible?

iaind · 20 Mar 2009 at 09:10

I cant see it being done as it's a very niche requirement. If there's not much animation content in the presentation you could use a thin client to RDP to the machine with the presentation. They can be wall mounted and are pretty cheap

K.C. Leblanc · 20 Mar 2009 at 09:28

It's going to be very hard to get the VM talking directly to the Graphics card. The only way this might work is if you used a USB graphics card (which are cack) since VMware server can pass USB straight to the VM.

I've got no idea if this would actualy work.

Just get a really small PC (HP DC7900 ultra slim perhaps?), or if you despirate to do this on the cheap buy a laptop with a broken screen.

mdjmcnally · 20 Mar 2009 at 09:33

The whole point of modern virtualization software such as ESX, Xen and Hyper-V is that they are so called bare metal hypervisors, in that only a very lightweight stripped down OS has access to the hardware. As such I cannot see them ever adding to ESX/ESXi

For your requirements then I would say that what you want is VMWare Server rather then ESX.

With VMWare Server then instead of using a lightweight hypervisor to interact with the hardware then it relies on a normal fat OS such as a full Linux or Windows Server.

As such your machine would startup Windows as normal, then would startup Virtual Server, (this can be automatically started), VM's can be configured to startup automatically as well.

You can then use the Windows Server OS as per normal.

This is not as good a virtualization solution as ESX as you are running Windows and then a Virtual solution on top of that, rather then a bare metal stripped down OS. That and Server is not as advanced as ESX in terms of resource sharing and high availability etc, but it would allow you to do what you want.

Personally however I would keep a proper VM Solution such as ESX as my VM, and then deploy a second machine to run the presentation from.

Five_Star · 20 Mar 2009 at 10:02

We use Microsoft Hyper-V already and the point that mdjmcnally made is probably the way we'll be going. We want to demo some full HD video on a loop which I wanted to do on a vista x64 machine due to the well supported video tools. I guess I'll have to investigate if this can be done on Server 2008 x64. I have already tested HD video over remote desktop and it can get pretty choppy.

I was hoping that as a well established virtualization provider, VMware would have to allow us to do what we wanted without the outlay on other hardware while still using a bare metal hyper visor and allowing a virtual Vista x64 to get full access to the hardware video card.

iaind · 20 Mar 2009 at 10:08

Five_Star said:
We use Microsoft Hyper-V already and the point that mdjmcnally made is probably the way we'll be going. We want to demo some full HD video on a loop which I wanted to do on a vista x64 machine due to the well supported video tools. I guess I'll have to investigate if this can be done on Server 2008 x64. I have already tested HD video over remote desktop and it can get pretty choppy.

I was hoping that as a well established virtualization provider, VMware would have to allow us to do what we wanted without the outlay on other hardware while still using a bare metal hyper visor and allowing a virtual Vista x64 to get full access to the hardware video card.

I think this is one situation where VMware is not the answer. Leave your server virtualisation separate from this.

Citrix and Wyse TCX will allow you to play HD video, but only if the client supports it.

For about £300 you can get a small form factor pc that would be capable of playing it, I think thats easily your best way forward

Five_Star · 20 Mar 2009 at 13:11

I've been looking at some cheap systems at lunch to run these demo videos on, having a look at where we are with servers and the current setup I think for £285 it's safer not to mess with our current VM setup.

Cheers