I have to admit to being a sucker for statistics (provided they’re well-founded, of course), particularly when trying to decide whether a theory is correct or not. Real data has a habit of being a far more reliable tool to decide an argument than a HiPPO, otherwise known as a Highly Paid Person’s Opinion.

I, therefore, make no apologies for there being actual, real graphs in this post.

A recent post by Brian Madden caught my attention, in which he asserted that “today the biggest share of these Citrix environments run on vSphere.” Admittedly, he was probably talking about XenApp, hence I’ll give him the benefit of the doubt, but I wanted to talk about XenDesktop.

Specifically, I assert that the majority of XenDesktop deployments are hosted on XenServer.

Yep, you read that correctly. And no, this wasn’t written on the 1st of April.

Before you reach for your browser to find a link to your favourite HiPPO blog, bear with me: I said I’d provide graphs, after all. Here’s the first:

XD Hypervisor Share Table

Hypervisor Share Under XenDesktop (Pie Chart)

These data are from Citrix’ telemetry functionality that’s built into XenDesktop 7.6. Evidently not everyone chooses to enable telemetry, but we have no evidence to suggest it’s not from a representative sample of the population (more on that subject later). I’ve taken a snapshot from the last 90 days, which consists of over 6,000 unique XenDesktop sites, globally: not bad, as sample sizes go.

To keep it simple, I’ve only labelled the three largest segments: the purple is Microsoft Hyper-V with System Center Virtual Machine Manager (SCVMM), the blue is VMware vCenter, and the green is Citrix XenServer.

Conclusion: XenDesktop telemetry data tells us that over 50% of XenDesktop 7.6 runs on XenServer.

OK, but there’s lots of holes one could pick in this:

  • Not everyone turns on telemetry. The sample is biased towards smaller deployments run by customers who might be less security-conscious.
  • These data are only XenDesktop 7.6. Not everyone’s upgraded to that, and those who haven’t are probably conservative people who run vSphere.

This is where I bring out some more statistics…

We have another way of looking at XenDesktop customers, which is collecting (anonymous) data about their deployments when they call our Support team, or use Citrix Insight Services, our free diagnostics portal where you can upload your log files to check for common problems with your Citrix product.

Back when I last checked, we had over 550,000 desktops-worth of data (and it’s certainly grown since then), hence it’s also a decent sample size. And it doesn’t suffer from the “I don’t turn on telemetry” problem. We looked into what the different deployment sizes in the sample set were: unsurprisingly, there are a lot more deployments of under 5,000 seats than over 10,000.

What I liked, though, was that of the four deployments of more than 10,000 seats (i.e. really big customers), three of them were on XenServer.

Alright, but this is Citrix data, and I might be fudging the numbers. I hereby reveal my independent statistician, Aaron Parker (a Citrix Technology Professional and Microsoft MVP from Down Under), who recently posted the results of his OS Automation Survey. Over on the results page, he posted the following breakdown of which hypervisor was being used under XenDesktop (not version-specific):

Aaron Parker's Survey Results on Which Hypervisor Runs Under XenDesktop

Clearly not just a phenomenon that Citrix noticed, then: more of XenDesktop runs on XenServer than on vSphere, according to the 724 responses that Aaron received.

He then dug into the deployment sizes, and found that for XenServer he had received:

  • 26 responses running 100 to 1,000 seats
  • 5 responses running 2,500 seats
  • 10 responses running 5,000 seats
  • 1 response running 17,000 seats
  • 1 response running 18,000 seats

(Full disclosure: there were 12 respondents on vSphere with more than 18,000 seats, hence as much as I might wish to claim all big deployments are on XenServer, I can’t just yet!)

Clearly, then XenServer is used in both large and small deployments, and not just by people who turn on telemetry.

So why is this? After all, Brian’s correct that many people deploy Citrix workloads on vSphere: it’s a very capable hypervisor, with a large share of the server virtualisation market. However, in the world of XenDesktop, where XenServer entitlement is included with all editions, plenty of customers are very happy running a full Citrix stack and not paying extra for the hypervisor. By the way, we include that entitlement with all editions of XenApp, too!

That’s not all, though: we’ve been busy making unique features for XenDesktop. XenServer was a very early player in the hypervisor caching arena, with Intellicache, allowing disk blocks from golden images to be cached, rather than every new desktop loading up the storage array, thus reducing storage costs. More recently, for 18 months XenServer was the only game in town with NVIDIA vGPU, and now we’re doing it again as the only hypervisor with support for Intel’s Iris Pro GPU virtualisation (GVT-g), which you can play with in the XenServer tech preview we’ve just released. Plenty more cool stuff being worked on!

If you’re not running XenServer underneath your XenDesktop deployment, why not give it a try? Installing XenServer takes under 10 minutes (or, if you’re quick, one breath!), and Citrix Lifecycle Management will make it the work of a few clicks to get a test XenDesktop deployment on top! You too can join the majority of XenDesktop users who use Citrix XenServer.