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About Windows Vista’s built-in hypervisor
By Michael Pietroforte | 5 Comments | Permalink | Trackback | Previous | NextBrian Madden wrote an interesting article about offline VDI (Virtual Desktop Infrastructure). However, I strongly disagree with the main point of his article; i.e., that we need a bare-metal client hypervisor for desktop management.
One of the major disadvantages of desktop virtualization is that that the end user’s device requires a permanent connection to the backend where the virtual desktop is running. Furthermore, display protocols such as RDP and ICA still have problems with many applications. Brian acknowledges these problems and speculates that bare-metal client hypervisors might solve these problems in the future.
If I understand him right, the idea is to run virtual desktops, not on servers, but on the client’s bare-metal hypervisor. This sounds like an interesting alternative. However, isn’t it one of the main benefits of VDI that you don’t require expensive fat desktops anymore? Of course, if you run Vista on a bare-metal client hypervisor, you require an even more powerful desktop computer because of the virtualization overhead. In addition, you have to deploy the OS to all of your desktops, just like you do it nowadays.
So what is the point of virtualizing a desktop OS on the desktop? This is Brian’s answer:
But the important take-away is that true desktop management bliss will require a client-side hypervisor BECAUSE we want to be able to run a single disk image on many different kinds of devices, and we don’t want to have to manage a second client OS in addition to our main disk image.
It is the “single disk image on many different kinds of devices” that is supposed to simplify desktop management. Regular readers of my blog have already probably noticed what is wrong about this argument. It is not first time that I have encountered this logic. Actually, the “single image argument” is often the first argument put forward when VDI supporters start enumerating the advantages of desktop virtualization.
I must admit that I find it rather strange that this argument is still alive two years after Vista’s release. It demonstrates that Microsoft has a real marketing problem with Vista. I think I am not exaggerating if I say that Vista revolutionized desktop management. What is fascinating is how few IT pros know about it or how many undervalue its importance.
The fact that a highly respected professional like Brian Madden talks about “single image”, without even mentioning that Vista has exactly this feature, shows that Microsoft really has to do more to spread the news about Vista’s imaging capabilities. In the way he talks about offline VDI, we have to conclude that Vista already supports it. Of course, you can use one Vista image for all kinds of devices including virtual ones. Thus, in this sense, Vista has a built-in bare-metal client hypervisor.
I already hear the Vista opponents out there: “But we don’t like Vista, we want Windows XP!” Well, do you really think it makes sense to introduce VDI plus a client-based hypervisor just because you don’t like Vista?
I think the “single image argument” in favor of VDI is made by someone unfamiliar with the finer points of sysprep.
I have a single deployment image for my Windows XP desktops *right now* – it works on plain IDE, non-AHCI ICH SATA, AHCI SATA, SAS, SCSI, RAID cards, etc; it covers everything from a lowly Dell Dimension 4100 to a Dell Precision T3400. Vista and ImageX make the whole process a lot easier (or so they say, I’ve never tried it).
I even have one of these deployment images for Windows 2000!
Wow, thanks for the article Michael! We’ve been using Vista with Ghost for about six months. This presents some interesting options. Unfortunately we have a mixed XP/Vista environment, and 75% of our users are off-site, so we cannot take advantage of Vista’s “one image” ideal of changing programs on the fly. Still, good to know.
Like you, I work for a college. The problem I see with your Vista argument, and the reason that we are very slow to move to it despite the student & faculty desire to have it, is that most of our existing PCs will not run Vista.
I don’t think any amount of PR can cure that problem.
[...] een enkel image kunt werken voor alle desktops. Over dit onderwerp publiceerde Michael Pietroforte pas nog een artikel met de stelling dat een enkelvoudig image ook heel goed mogelijk is zonder hypervisor eronder: The [...]
Phil, yes, if you are lucky, then you can work with just one image for all your XP machines. But this doesn’t always work. We experienced numerous cases where we ran into problems. Vista images are hardware independent by design. This is not the case for XP. We use cloning technology since Windows NT 4. It took Microsoft quite some time to understood that this is the best way to deploy an OS.
MattA, Ghost was the first cloning tool I’ve ever used and if I remember it right it was the first cloning solution for Windows. It must have been in another century. Good to know that it is still alive.
Dave, you won’t believe that there are still quite a few NT machines out there for the same reason. Of course, it takes some time until old hardware can be replaced. It was always like this. I blogged about this topic a while back.