I’ve long been opposed to the VMware ESX EULA restriction on publication of performance comparisons between VMware’s products and those of its competitors.   VMware clearly believes that “it’s all too complicated for normal users” so you can only publish comparative results if you first get VMware’s approval, which tells me that (a) they underestimate their users and (b) they likely have something to hide.  And judging from the VMware VMTN forums, many of their users agree.    By contrast, our view is that if we (either in xen.org or in XenServer) have a performance or security issue, then we’d like to see it publicized as loudly as possible, because it will get fixed sooner that way.   Even VMware IHVs and ISVs can’t publish their own performance comparisons with VMware (let alone other products).

When we launched XenServer 5, we used independent performance consultancy The Tolly Group to verify our claims of vastly superior performance for XenApp/Windows Terminal Server environments virtualized on XenServer, by comparison to other virtualization platforms.  Both Citrix and Tolly Group requested permission from VMware to publish comparative results.  Those requests were denied.   Nonetheless, we claimed on the basis of the Tolly tests that XenServer is up to 70% more efficient than other virtualization platforms for this workload (a mere million or so servers, worldwide it turns out).  But we still really needed an entirely independent, technically qualified validation of our claims – and other virtualization performance claims in general.

 In that spirit, it is a great pleasure to welcome the contribution of two of the smartest virtualization practitioners in the value-added reseller community, Jeroen van de Kamp of Login Consultants, and Ruben Spruijt of PQR have launched Project Virtual Reality Check to provide independent, thorough, validated and vendor neutral performance data for virtualized environments.  To quote Ruben:

“This is an independent research joint venture between our companies Login Consultants and PQR. The primary purpose of VRC is to release multiple whitepapers to provide information about the scalability and best practices of virtualized Terminal Server and Desktop workloads. The first phase of Project VRC on virtualizing Windows XP and 32-bit Windows 2003 Terminal Services on ESX, XenServer and Hyper-v. The whitepapers can be downloaded freely from www.virtualrealitycheck.net. The goal of Project VRC is to investigate, validate and give answers to the following questions:

  • How do various Microsoft Windows Client OS’s scale as a virtual desktop?
  • How does a VDI infrastructure scale in comparison (virtualized) Terminal Server?
  • Which performance optimization on the host and guest virtualization level can be configured, and what is the impact of these settings on user density?
  • With the introduction of the latest hypervisor technologies, can we now recommend running large scale TS/CTX workloads on a virtualization platform?
  • How do the two usage scenarios compare, that is Microsoft Terminal Server [TS] only, versus TS plus XenApp?
  • How do x86 and x64 TS platforms compare in scalability on bare metal and virtualized environments?
  • What is the best way to partition (memory and vCPU) the Virtual Machines the hypervisor host, to achieve the highest possible user density?

All together over 150 test have been carried out. However, project VRC is not finished, and probably never will be. Additional publications are planned about virtualizing x64 workloads and the other (Vista and Windows 7) client OS’s. Also, we look forward to evaluate new innovations in the hypervisor and hardware arena.”

Hats off to these guys for making this  a freely available resource and for contributing their expertise for the benefit of the virtualization user-community.   They will doubtless be talking about this in more detail at the upcomingVirtualization Congress - the industry’s firstvendor neutral virtualization showcase. 

It will be fascinating to see the VMware response.  If they’re smart they’ll embrace this effort.  So who knows what to expect?