Free VDI options for KVM hypervisor

Most VDI deployments in enterprises run with VMware Horizon View, or Citrix XenDesktop, or with smaller or up and coming market players such as Parallels, Ericom, and Workspot.

However, I see an increasing request for a KVM supported VDI solution. Customers want to run VDI on KVM, eliminating hypervisor license costs, therefore reducing the total cost per desktop. Furthermore, it’s also possible to remove Microsoft licenses if Linux is used. Cost per desktop has been one of the factors playing against VDI adoption and leading to many ROI discussions.

I started looking at VDI alternatives for KVM and was able to find solutions that could fit the bill for some organizations. Most commercial VDI solutions that broker connections to stand-alone machines, virtual or physical, are also capable of working with desktops hosted on KVM hypervisor. However, for this article, I am focusing on solutions that will provide zero dollar software cost (except for Microsoft Windows OS).





  • Ravada VDI Project [Update 4/10/2017]

The engineering team from the Universitat Politècnica de Catalunya. BarcelonaTech created a Linux-based VDI solution for qemu-KVM. In their website the Ravada team specify the features available today and on the roadmap.

The solution is simple to install and operate, and the display protocol of choice is KVM spice. The client must have a spice viewer such as virt-viewer. The source code and binaries are available on GitHub, and they welcome contributors.


Pros: Free brokering and hosting solution for KVM.

Cons: Not tested at scale.



  • Open UDS [Update 4/10/2017]

OpenUDS Is an Open Source Source project, initiated by Spanish Company Virtualcable and released Open Source with the help of several Spanish Universities. UDS Enterprise is a multiplatform connection broker to manage and deploy virtual and physical desktops, applications and other Windows & Linux services. It supports XenServer/XCP, KVM, and ESXi hypervisors.

Project website:

The source code and binaries are available on GitHub.


Pros: Free brokering and multi-hypervisor support






  • KVM-VDI [Update 01/01/2016]

The team at Vilnius University in Lithuania contacted me about an open-source project they have been working on. The University developed a KVM based VDI solution for their computer classes.

The project uses qemu-KVM virtualization and provides VM based sessions with native soft clients via SPICE or RDP protocols. The broker is also able to provide access to virtual desktops created via a VMware Horizon VDI pool on vSphere.

Nice work by the folks at Vilnius University, and for now anyone can test it on any KVM hypervisor or Acropolis. The source code and binaries are available on GitHub.

Also, read New KVM-VDI Open Source Project.


Pros: Free brokering and hosting solution for KVM.

Cons: Not tested at scale.







  • Stand-Alone Windows VMs

Virtual desktops are nothing more than virtual machines running Windows or Linux operating systems. Virtual machines with remote display protocols enabled can be treated and accessed as virtual desktops.

Some Nutanix customers decided to use KVM to host stand-alone virtual machines manually provisioned. They use NetBIOS and DNS resolution to allow users to access their desktops. Therefore each user must know or be pre-configured with the virtual desktop FQDN. For this end, they are using a common naming classification for desktop naming that uses the employee’s ID.

Since they use only Windows 7 desktops, they are using RDP, but Linux desktops could also be used with xRDP as an example.


Pros: Zero brokering and hypervisor cost with a simple approach. Windows Remote FX is now a good enough protocol for the large majority of use cases.

Cons: The solution requires individual desktop and DNS management, therefore easy to scale management. There’s no ability to use advanced remote protocol or VDI capabilities; such as auto refresh and recompose.




  • Ulteo

Ulteo Open Virtual Desktop (OVD) is a free application delivery platform that uses Windows Remote Desktop Services to publish desktops and applications. Ulteo offers access to Linux hosted desktop and application sessions. Ulteo integrates and seamlessly deliver sessions as a secure service to clients based on Windows, Linux, MacOS, Android, and IOS. After some fiddling with the installation, I was able to publish Linux applications and Windows applications and desktop successfully.



Pros: Free solution to deliver a session based application in Windows or Linux. The solution works decently on a local LAN, but not recommended for remote use cases.

Cons: VDI using individual virtual desktops is not supported. It looks like Ulteo has been recently acquired and support may be available soon.



  • Crossroads

Crossroads is an open source load balance and fail over utility for TCP based services. It is a daemon running in user space and features extensive reconfigurability, polling of back ends using ‘wakeup calls,’ detailed status reporting, ‘hooks’ for special actions when backend calls fail, and much more. Crossroads is service-independent: it is usable for HTTP(S), SSH, SMTP, DNS, or RDP connections. More info: This approach will allow for persistent and non-persistent desktop access, but the VM management, if needed, must be done manually.

Theoretically, most load balancers nowadays have this capability, but according to the article linked above the author introduced some special support to use the load balancer as a desktop broker. I will soon test the solution and write another article with my review.



Pros: Zero brokering and hypervisor cost with a simplistic approach. Offers connection load balance for non-persistent desktops. Windows Remote FX is now a good enough protocol for the vast majority of use cases. The solution does not require manual DNS management.

Cons: If desktop management such as recompose and refresh is necessary for you may want to use a commercial solution, but it’s also possible to automate a desktop refresh every night using SYSPREP, snapshots, and scripts.



In the examples above when Windows is used as the operating system, it is possible to have Active Directory integration and authentication, printing (albeit not universal), USB sharing and a good enough remote experience. Microsoft has made its remote desktop client available for many platforms, including iOS, Mac, and Android.

Commercial products offer many advantages, but for companies looking for a cost-effective alternative running on KVM should consider one of these options. Please note that other solutions such as Leostream will support KVM using Red Hat Enterprise Virtualization (RHEV).

If you are using another method, not listed here, to deliver VDI, please let me know.


This article was first published by Andre Leibovici (@andreleibovici) at



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    • Riccardo Pelliccioli on 04/05/2015 at 8:25 am

    Always liked VERDE from VirtualBridges (recently acquired from NIMBOXX) for his clean and distributed design…unfortunately not suitable on NUTANIX and not FREE

    • Seppo on 01/26/2016 at 10:50 am

    Even if you don’t use RDP to connect Windows graphical interface but use any other means to connect remotely to Windows graphical UI you would still need to pay for Remote Desktop CAL license. There is no way to go around this in VDI scenario.

  1. That’s is true. In this case the only way is to use Linux virtual desktops.

  2. Hi,
    First thank you for your study and all your comments.
    It is always great to get feedbacks.
    Then, as new Ulteo GM, I do confirm Ulteo has been acquired by AZNetwork Group in 2015.
    Now, the team is up and running and working hard on developping and supporting partners and customers.
    We just launched a new release (beg of apr’16) and a new one is going to be launched before the end of this year with a lot of surprises.
    Do not hesitate to contact me directly if you have any questions!

    • Dongho on 07/31/2016 at 6:27 pm

    By the way, I am wondering whether enterprise and public markets for VDIs are still growing or are saturated ?

  3. Dhongo, I am not a market analyst so I can only speak to my experience at VMware designing Horizon View and at Nutanix selling infrastructure to also support VDI deployments. I see a increasing number of companies looking at VDI as a way to provide additional security and data governance to their local and remote workers. There are many industries heavily relying on VDI; such as healthcare and finance. The deployment are getting much bigger, some past 150k desktops. I personally believe the market is still growing, but not as fast as few years ago.

    • johnp on 09/26/2016 at 5:38 am

    Here’s another Open-Source Multi-Hypervisor, Multi-Protocol VDI solution:

    Commercial support runs under the name UDSEnterprise at

    but the difference in functionality is rather small:

    The wiki-article, being last updated April 2015 is a bit out of date, and by now there are many more features:

  4. There is also our advanced enterprise Open Virtual Desktop solution at Inuvika.

  5. I know this is an older article but this is the one I used at my old company and it was reliable and we had over 300 people on the ovirt cluster. This is a great blog thanks for sharing your knowledge and experience.

  6. Kevin and William, this one doesn’t seem to be a free option as the name of the article says.

  7. Inuvika’s OVD has a community based foundation version that is free, but the enterprise version is not. It is about half the price of VDI alternatives.

    • fv3r on 04/04/2017 at 1:16 pm

    RavadaVDI is an open source VDI see the code in github.

  8. @fv3r thanks for the tip. I’m looking at it and will add to the list.

    • PRABHURAJ M on 05/24/2017 at 7:29 am

    how to install kvm-vdi please guide me

    • Hub-AC on 07/10/2017 at 7:45 pm

    This was a very helpful article. A lot of these Spanish options have not come up in my search in the US. Thanks for taking time to go through and compile these free solutions.

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