Why Isn’t Desktop Virtualization More Widely Adopted?

I attended an interesting session at Citrix Synergy earlier today. It was conducted by Ron Oglesby, Chief Solution Architect of Unidesk, and the subject was why desktop virtualization has not taken off like server virtualization has. This is something I’ve wondered about myself, so I was eager to hear someone else’s view on the subject. Since a lot of the points he made could also be classified as “things to watch out for,” I thought others might also find it interesting.

First of all, it is important to recognize that “Virtual Desktop” does not equal “VDI.” (And by “VDI,” I mean turning your physical PCs into virtual machines that are running on some kind of hosting infrastructure, such as VMware, XenServer, or Hyper-V.) VMware has done a pretty good job in many cases of framing the conversation as though these terms were equivalent, because VDI is what they do, and it’s in their best interests to frame the conversation that way. Hats off to them for the degree to which they’ve accomplished that.

But VDI is just one form of desktop virtualization. The fact is that we’ve been virtualizing desktops since the debut of WinFrame a decade and a half ago. And it can be argued that XenApp is still the most cost-effective way to virtualize a desktop. I can pretty much guarantee that, on a given piece of server hardware, I can support more concurrent users with XenApp than I can by building individual virtual PCs.

But what seems to be happening in some cases is that management has seen the tremendous cost savings that have been achieved through server virtualization, so they decide that they should virtualize desktops the same way they virtualized servers, expecting that they will see the same kind of dramatic cost savings. Often, they are painfully disappointed.

Dramatic cost reduction through server virtualization is a no-brainer. You take a bunch of servers that are already in the data center, most of which are probably idling along at less than 10% processor utilization (if that), and consolidate them onto a smaller number of servers. You save space. You save power (both the power it takes to run the servers and the power it takes to cool them). You gain agility and fault tolerance through things like live motion technology. The CAPEX (capital expenditure) savings are obvious. You can probably show a positive return on investment in the first year.

Near-term CAPEX savings are almost impossible to show in a VDI project, because of the back-end infrastructure you have to put in place to host your virtual desktops. (Note that we’re talking here specifically about VDI as I defined it earlier in this post.) Your savings are primarily in ongoing operating expenses, and (according to the Burton Group in a different session I attended) it may take as long as 3 – 5 years to see a significant ROI. Beyond that, you’re talking about things that are very hard to quantify at all, such as the benefit of giving your employees the flexibility to be productive from anywhere. Great idea, difficult to quantify.

Unless you are using some kind of tool that will let you provision multiple virtual desktops from a single shared image, your storage costs are going to skyrocket, because you’re replacing cheap SATA storage on the desktop with expensive SAN storage in the data center – and a Windows 7 image with all the apps on it can easily run 30 Gb. Moreover, the way a desktop OS uses storage is completely different from the way a server uses storage. Your typical Windows server probably averages about 5 IOPS (Input/Output Operations Per Second), with a read/write ratio of 2:1 to 3:1 (more reads than writes). A Win7 system averages more like 30 IOPS, and the read/write ratio is just the opposite.

In other words, workstations aren’t servers, and they won’t behave like servers just because you move them into your data center and put them on a SAN, and therefore you can’t treat them as though they were servers. If you do, you probably won’t be happy with the result.

Finally, although IT guys love standardization, users don’t. They’re used to being able to personalize their personal computers, and they won’t easily give that up. And they definitely won’t be happy if all of the personalization they’ve done suddenly disappears when you replace their PCs with virtual desktops. Unfortunately, there is no magic wand you can wave that will transform a bunch of diverse PCs that have been highly personalized into a single shared image while still preserving all of the personalization. There are some tools that will help you with this, but you have to plan, you have to test, you have to be careful, and you need to have a roll-back plan.

So does this mean that desktop virtualization is a bad idea? No, not at all. It does mean that you need to take the time to understand your users, and come up with a desktop strategy that encompasses all of your use cases. And you need to recognize that classic VDI is probably not a “one-size-fits-all” solution for all of your users:

  • Task-based workers (e.g., call centers) are probably very well served by “Hosted Shared Desktops,” a.k.a., virtual desktops running on XenApp servers.
  • Remote workers may also be covered by Hosted Shared Desktops, although those who need more power, or need the flexibility of a dedicated OS, may be well served by a hosted virtual PC – traditional VDI. For example, a contract programmer may be a continent away, and may need the ability to do things that cannot be done on a shared server OS, like modifying the registry or rebooting the system, but the employer may also want the security of knowing that the code never leaves the datacenter. VDI is a perfect solution for this use case.
  • Office workers may be served by hosted virtual desktops (VDI), but could also be served by streaming the PC operating system from a central shared image directly to the PC hardware on their desks. Managing that central image beats running around to all the desktops with a backpack full of CDs to do your upgrades!
  • Power users who might, for example, need the power of a dedicated 3D graphics processor might be best served by streaming a central shared image to a blade PC in the datacenter, which the user then accesses via a thin-client desktop device.
  • Mobile users, by definition, need to work when they’re not connected to the corporate network. This is the use case addressed by XenClient.
  • In all of the cases above, having a provisioning tool that allows you to boot and run multiple systems from a single shared image is going to save you a bundle on storage.

The cool thing about XenDesktop 4 is that you can handle all of these use cases, and mix and match the best virtual desktop deployment method to each group of users, and they’re all included in your XenDesktop 4 Enterprise or Platinum license. No other vendor offers that flexibility.

16 replies
  1. Adam
    Adam says:

    You are correct that desktop virtualization goes beyond just VDI. The fact is that Terminal Server has advantages over VDI, while VDI also has advantages over Terminal Server. That’s why most organizations are best served by adopting a hybrid approach, with an optimal mix of Terminal Server (for task-oriented users), VDI (for power users), and Blade PCs (stock traders, graphic designers, etc.) which delivers the most benefit and platform flexibility to the organization.

    Note from Blog Admin: The balance of this comment has been deleted because, in our judgment, it crossed the line between providing information and trying to use our blog to promote your product. However, organizations that need to manage a mixture of virtualization methods may want to note that Ericom has a product, “PowerTerm WebConnect,” that is specifically designed to manage mixed environments. ManageOps does not have direct experience with this product, and therefore does not endorse it. Those who may want more information can find it at http://www.ericom.com.

  2. Dean Flaming
    Dean Flaming says:

    I think one of the other big underlying issues is User Entitlement.

    IMHO many users don’t want to give up their laptop/desktop/tablet for a virtual desktop….fearing they will be limited in functionality. Nor do they want to give up their apparent “right” to install whatever, whenever, however, wherever they want.

    In talking with a customer awhile back, I asked if they had rolled back local admin permissions and the answer I got was, “We did…for about a week. Then the CEO walked in and said, ‘I want users to be able to install apps when they want!’ We tried explaining it but he wouldn’t listen.” None of this was very surprising to me – what was surprising was after studies were done and results were shown how it was far more costly (in hours and $$) to allow local admin permissions, the CEO still decided to allow all users local admin permissions…so it boiled down to User Entitlement.

  3. Robert Kadish
    Robert Kadish says:

    I agree this is a great perspective! One area I think is worth exploring more are solutions to reduce IOP’s requirements.

    Of course I have a vested interest in this area as I work for Atlantis Computing. However there are several different ways to reduce IOP’s and all will have an impact TCO/ROI.

  4. Eric Hanselman
    Eric Hanselman says:

    Sid – As Harry and Ron said, great perspective on how many solutions are really available for Hosted and Virtual Desktops (HVD, not to get too Gartner-ish). There are even options outside of Windows as we see more interest in Linux desktops.

    One great benefit of VDI/HVD is that it delivers the flexibility to target different user communities with computing solutions that meet their needs and IT budgets. To be successful, we’ve got to offer something that our users actually want to use.

  5. Sid Herron
    Sid Herron says:

    Harry & Ron – Thank you both for your comments. This is precisely the kind of exchange of ideas we had hoped would develop when we launched our blog!

  6. Harry Labana
    Harry Labana says:

    Ron, finally getting a chance to read other views after a long CITRIX CITRIX CITRX week 🙂

    I agree personalization in many respect is the wrong word. Too narrow. I think it’s more about simplifying the desktop full stop. IMHO, that’s the bigger goal we must all strive towards if we want to realize hard cost benefits of desktop virtualization.

  7. Ron Oglesby
    Ron Oglesby says:

    Harry! trolling the blogs I see!

    Anyway, I think personalization is the WRONG word. But my vocabulary is too limited to find a new one. I can agree that in large (risk minimizing) orgs that lock down the desktop traditional personalization often is shunned. BUT, personalization is not profiles (as we both know) and things that we don’t think of as “user stuff” is getting wiped out with PVS or linked clones (Think encrypted keys in HKLM added by apps, GUIDs for Symantec enterprise or other End point mgmt and monitoring apps).

    Often we hit the issue with hammer. Maybe different hammers like a trim hammer, or framing hammer or ball peen hammer, but always a hammer. But sometimes… the problem isn’t a nail. It’s a bolt.

    With that said someone I had dinner with in NYC once said that a CTO’s job was to take an idea that isn’t real and try to sell it and turn it into reality. Kind of like CTXS’s Anywhere Any Device back in like 2000… Allowing personalization (IMHO) is one of these things. Enabling users? Pulling them into the environment vs Pushing them. We’ve tried pushing VDI. It’s time to pull.

    Had a good time at Synergy. Sorry I missed you there.

  8. Harry Labana
    Harry Labana says:

    This was a good post. You hit the nail on the head by understanding that Desktop Virtualization is not VDI alone. I will argue though that in most managed the organizations, the amount of required personalization is not as broad as one may first assume. They also don’t typically bother with SAN due to the cost. That’s fud that was put out there by EMC to sell storage with VDI. This is why they are seeing traction. For smaller unmanaged environments it’s a different can of worms, that is getting good attention.

  9. Ron Oglesby
    Ron Oglesby says:

    Sounds like you got it all! of course I think XenDestkop gets you REALLY close. We help out Xen by “finalizing” the VDI portion of their solution by allowing Single image mgmt (big deal) but still allowing personalization all the way to user installed apps (even bigger deal). I didnt really “pimp” this in my session as we were discussing VDI in general, but figured a shameless plug here would be OK!.


  10. Sid Herron
    Sid Herron says:

    George – I think we’re on the same page here in regard to the VDA license. As I said earlier, I’d really like to see a perpetual license as an alternative to the subscription license.

    And there is hope that the license model will evolve with time. Some of us remember that Microsoft’s initial position in regard to NT4 Terminal Server Edition was that since it was another way of deploying what was effectively an NT4 desktop, if your client device was not already an NT4 Workstation, you were REQUIRED to purchase an NT4 Workstation license for it, no matter what it was. After being blasted by the user community, they changed course and introduced the Terminal Services CAL model. Sometimes it just takes a while (and a lot of customer feedback).

  11. George
    George says:

    Sid – Thanks for the reply. The VECD/VDA license for Thin Clients is priced for the Windows 7 Enterprise functionality which you may argue it provides. It’s cost is however double that of Open Value Subscription on a Windows Pro desktop, and those keep piling up.

    On the desktop side this eats up any advantage within three years if you don’t count desktop management advantages.

    Given the considerable investment you need to make on the datacenter side, the client side advantages will not contribute to offsetting those expenses.

    Last month I had the MS Call Center e-mail me that I could move SA from a Windows Pro desktop to a Thin Client replacement; NOT the case ofcourse, but that would have been neat.

    I don’t mind VDA licensing but fail to see why it has to be more expensive then licensing a desktop system with SA (and thus VDA). That OEM license we’re “saving” isn’t where the advantage lies.

    One can only hope MS will in time bring cost more in line with “regular” desktop licensing.


  12. Sid Herron
    Sid Herron says:

    @George – Thanks for your comment. Please remember, though, that sometime after July 1, you will not be required to purchase a VDA if you have SA on the desktop. VDA is required only if your endpoint is NOT a desktop covered by SA. So, if your endpoint device is a PC (as opposed to some kind of thin client), it can be argued that SA brings EVEN MORE value now…and there are several virtual desktop scenarios where the endpoint is still a PC.

    That said, I’d still like to see a perpetual VDA license option as an alternative to a subscription license – but that probably won’t happen unless Microsoft gets strong push back from a lot of customers. It doesn’t make a lot of sense to me that, if I want to use a Wyse thin client to access a desktop that’s virtualized through Remote Desktop Services (a.k.a. Terminal Services), I can buy an RDS CAL for $80 or so and be done with it, but if I want to use that same Wyse thin client to access a virtual Win7 desktop, I have to pay Microsoft $100/year forever.

  13. George
    George says:

    Lets not forget that Microsoft licensing also penalizes you heavily for not running or accessing Windows on/from “PC” hardware.

    Since their WIndows (and Office) licensing is still device based (without a user option), this “makes sense”. The current work arounds they provide with VECD (soon to be VDA) are expensive subscriptions compared to common Windows licensing (OEM+SA).

    This demand for premium licensing pricing for VDI scenario’s is in no way warranted by value added to the solution by MS. This in contrast to other licensing extensions, such as SA and MDOP, which provide additional value to solutions.



Trackbacks & Pingbacks

  1. […] a VDI solution, by which I mean a bunch of virtual PCs running on one or more virtualization hosts. As we’ve discussed in other posts, VDI is only one kind of desktop virtualization. If you want the flexibility of being able to […]

  2. […] a VDI solution, by which I mean a bunch of virtual PCs running on one or more virtualization hosts. As we’ve discussed in other posts, VDI is only one kind of desktop virtualization. If you want the flexibility of being able to […]

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