July 12, 2011 - Sven Huisman

XenDesktop says goodbye to vSphere? (update 2)

In a lot of VDI deployments VMware vSphere is used as the hosting platform. There a couple of reasons that you can think of about why this is:

  • The company uses VMware vSphere as a platform for virtualizing their servers. They don’t want to manage other types of hypervisors for the VDI environment, so they want vSphere for their VDI as well.
  • VMware vSphere has multiple memory management technologies (TPS, ballooning, Memory compression) which work extremely well in an environment where the VM’s are very similar.
  • In case of VMware View, there is no choice of hypervisor, vSphere is the only option.

In case of Xendesktop deployments (or Quest vWorkspace or other VDI vendors that supports vSphere), VMware vSphere is often used because of the first two reasons. This may change this year, unless VMware takes action.

UPDATE: I’ve just learned that VMware will release a Desktop edition of vSphere 5. This is very good news!

A vSphere Desktop edition – This was quietly added on the partner SKU list for non-View VDI implementations.  This provides a low cost hypervisor for XenDesktop implementations (a fairly common occurance).” (source: Knudt Blog)

Now with vSphere 5, a new license model is introduced. This new license model introduces “vRAM Entitlement”. An explanation:

We have introduced vRAM, a transferable, virtualization-based entitlement to offer customers the greatest flexibility for vSphere configuration and usage. vRAM is defined as the virtual memory configured to virtual machines. When a virtual machine is created, it is configured with a certain amount of virtual memory (vRAM) available to the virtual machine. Depending on the edition, each vSphere 5.0-CPU license provides a certain vRAM capacity entitlement. When the virtual machine is powered on, the vRAM configured for that virtual machine counts against the total vRAM entitled to the user. An important feature of the new licensing model is the concept of pooling the vRAM capacity entitlements for all processor licenses. The vRAM entitlements of vSphere CPU licenses are pooled across all CPU licenses managed by a VMware vCenter instance.

What does this mean for Xendesktop deployments on vSphere? A couple of examples:

I need to host 500 Windows 7 desktop VMs on a cluster. Each VM needs 2 GB of vRAM. Suppose I can host 7 VMs per core and I use servers with 2 CPUs with 6 cores each. Per server I’m able to host 2*6*7= 84 VMs. Because of the memory technologies used in vSphere, I don’t need 84 x 2GB = 168GB RAM in each server, but 128GB RAM should be enough (I know, it depends, but it’s just an example). Using 6 of these servers, I’ll be able to host 504 VM’s.

  • Total number of VMs: 504 VM’s
  • Number of hosts: 6
  • CPUs per host: 2
  • Cores per CPU: 6
  • Memory per host: 128GB
  • Total amount of CPU sockets: 12
  • Total amount of vRAM needed: 504 x 2GB = 1008GB

The question is now: which vSphere 5 license do I need for my VDI hosts? I have three options and each option gives me the right to allocate a certain amount of vRAM per CPU socket:

  • vSphere Standard: 24GB vRAM per CPU socket
  • vSphere Enterprise 32GB vRAM per CPU socket
  • vSphere Enterprise Plus 48GB vRAM per CPU socket

Distributed Resource Scheduler (DRS) and Distributed Power Management (DPM) are features which are often demanded in a VDI environment. These are features that are part of the Enterprise and Enterprise Plus license. If I look at the number of CPU licenses I would need, I can calculate how much vRAM I can allocate. 12 x 32GB RAM = 384GB RAM. That’s not enough to host all of the VMs. Even when I take a vSphere Enterprise Plus license, I can only allocate 576GB of vRAM. In this situation, I need 32 vSphere Enterprise licenses or 21 vSphere Enterprise Plus license instead of just 12!

Now what will happen? There are a couple of options. Current Xendesktop deployments on vSphere will probably migrate to Hyper-V or Xenserver or will stay on vSphere 4 for as long as this platform is supported. New Xendesktop deployments will not even think of using vSphere 5. A side effect of this can be that the hosting platform of the servers will also be migrated to Hyper-V or Xenserver, because it isn’t an option to maintain 2 different types of virtualization platforms.

It still possible that VMware will offer a VDI-license which can be used for Xendesktop deployments. The same license is used with VMware View, which is a per concurrent user license for vSphere. This license is intended for desktop OS VMs only. Time will tell if VMware will make this VDI-license available as a separate license (instead of only including it with VMware View).

Update 2: there is now a document published which explains about the vSphere desktop Edition. It’s $65 per powered-on desktop, you buy in 100 packs. Blogpost coming up with new calculations!


Virtual Desktop License / VDI / VMware / vSphere 5 / Xendesktop /


  • Craig says:

    The cost is outrageous. Today’s announcement is great day for other VM providers, they will be getting plenty of business based on this bone headed move by vmware. If the licensing model was tied to memory in use, maybe, but it is memory allocated to VMs which is a non-starter. No more over provisioning memory or if you do, pay up. It takes one of the most valuable features of vmware and makes unusable. Thanks for nothing vmware, take your vsphere 5.0 and shove it.

    • Sven Huisman says:

      To be clear: you can still overcommit on memory, that is allocate more RAM to the VMs than available in the server. The license is for the vRAM: the memory you allocate to turned on VMs.
      But still, it’s a big increase in price in most situations I think.

      • John Pace II says:

        You are playing games here. The overcommit of memory made VMWare a good value proposition, but the additional cost of VMWare server when overcommiting memory makes it horrendously expensive. For example, you could add 32GB of vRAM overcommit to a Dell R910 server for $3594. That doesn’t get you a single bit of memory, just the ability to overcommit 32GB. With that same money, you could add 236GB of REAL RAM to that server and load a huge amount of virtual machines. With these type of resources, small VMware efficiencies mean nothing. Just to complete the numbers, adding 236GB of RAM under the new VMware licensing model would cost $25,439 campared to $3594 with Microsoft Hyper-V or Xen. by comparison, a maxed out Dell R910 4U 4TB Server with the fastest processors and 256GB of REAL RAM only costs $24,720. VMware must be insane to believe that the industry is going to accept these losses in order to purchase vaporRAM.

  • John Kramer says:

    I agree this totally negates over provisioning of RAM on physical servers, With Vsphere 4 I have the option to double my physical RAM without additional licensing costs. Now VMware has taken that cost advantage way and will use it to drive revenue growth(or loss if nobody bites, I know we can hope can’t we?) This is a KILLER for VDI deployments.

  • Sean_D says:

    The way VMware’s desktop product is licensed with vSphere 4, customers can use as much vSphere as necessary in order to host the # of desktops they’ve licensed. I don’t see why they’ll change that model with vSphere 5 – so if you purchase 100 View licenses you’ll be able to load vSphere on as many servers as that number requires. So… put your shorts back on and understand what you’re talking about before you flame.

    • Jeff Couch says:


      You should read before you post since thats not what the article says. He is discussing Xendesktop deployments using vpshere as the hypervisor instead of xenserver. This changes our deployment plan for xendesktop (since view is not an option for us). We will now have to look at xenserver as a hypervisor for the exact reasons pointed out above.

      • Sean_D says:

        That’s my point Jeff. When you host desktop workloads – whether View or XD, you have the ability to use vSphere for Desktops as the platform, and that includes all-you-can-eat vSphere Enterprise Plus licenses. Thus vRAM is still not an issue since the license model for desktop workloads is different. I’m assuming, of course, that it’ll remain the same with vSphere 5.

        • John Pace II says:

          Sean, you obviously haven’t heard the news. VMware is now charging for and limiting both RAM and CPUs. For real numbers, see my post above.

    • John Kramer says:

      Yeah Sean how much RAM are you going to be entitled to for those 100 view licenses? What if your buy the View Licenses as an Add-on to existing vSphere licenses?

      • Sean_D says:

        Why would you do that John? If you have existing vSphere licenses and want to add desktop workloads, you should purchase vSphere for Desktops instead of the add-on. The underlying entitlement is vSphere Enterprise Plus and will be counted as its own pool of vRAM. The best bet is, of course, to check with VMware themselves but this action makes the most sense given the scenario you outlined.

        • John Pace II says:

          Again I will point this out. VMWare vSphere Enterprise Plus 5 only allows for 48GB of assigned vaporRAM (whether that is REAL RAM or overcommit doesn’t make a difference for licensing). Now, if you are running 100 Desktops with 1GB of committed RAM each, you will have to purchase 3 Enterprise plus licenses at over $13.000. Oh, I almost forgot. That $13,000 doesn’t get you any RAM, you still gotta buy that anyway.

        • John Pace II says:

          Sorry, I see that the desktop licensing, at present time, will only cost you $6500 for 100. This means that desktop licensing is not as bad as server visualization, but that still doesn’t change any of the numbers that I posted.

  • Alex says:

    Most of our customers have server with 2 QC CPUs and 96 GB or 144 GB RAM. Now they need 2 vSphere 4 CPU licenses per server. With vSphere 5 they will need 2-3x more licenses. No go for VMware.

  • Sean_D says:

    Thanks for updating your article Sven. You were right to raise the _potential_ issue, but I think it had the net effect of getting several folks (Jeff, John, Craig?) all worked up about nothing. Keep the good stuff coming!

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  • LLee says:

    Within 2-4 years, Hyper-V and or XenServer will reach parity in features with VMWare. It’s licensing decisions will be short-lived at a cost of losing many customers, evangelists, and future opportunities. They are thinking short-term instead of long-term. Great new features killed off by dumb management decisions. Great Engineering but, terrible management decisions…

  • LLee says:

    BTW, Thanks to this change in licensing, I found an excellent alternative with Proxmox! It utilizes KVM with an intuitive interface. Thank you VMWare!

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