Wikibon’s Dave Floyer published an excellent article today featuring an in-depth economic comparison of two approaches to VDI. In the left corner are the new Dell XC Series Web-scale Converged Appliance models targeted at VDI use cases. Floyer refers to these models as Nutanix-powered converged VDI application appliances. And in the right corner are white box servers (such as Supermicro) plus VMware VSAN.
Are SANs for Virtual Desktops Officially Anachronistic?
It is amazing how quickly datacenter is evolving. In August of 2013, I wrote a Wikibon piece describing why hyper-converged infrastructure enables a positive VDI ROI whereas conventional compute + storage solutions are almost always a bad idea. Back then, Nutanix was really the only hyper-converged game in town.
Fast forward 15 months, and the hyper-converged space is suddenly crowded. Dell, of course, has the XC Series while VMware has VSAN. But VMware also makes VSAN available as EVO:Rail to several hardware manufacturers including EMC, HP, Supermicro, Dell, Inspur, Fujitsu and Net One Systems. HP, meanwhile, has given its Left Hand VSA a makeover – it’s now StoreVirtual. There are new software-only hyper-converged startups such as Maxta and SANbolic. Pure Storage has announced an upcoming hyper-converged solution. Even Cisco is getting into the game with an investment in Stratoscale.
The Wikibon article doesn’t address traditional infrastructure or SANs at all, simply stating that, “delivering software-led infrastructure as a converged appliance significantly reduces IT costs.” The implication is (at least the way I read it) that SANs are obsolete technology when it comes to virtual desktops.
Three Year TCO Analysis
Dell has not yet published any information about its upcoming XC Series bundling of the compute, storage, hypervisor and VDI broker (what Floyer calls a “single managed entity”). Floyer says that the Dell solution will include either VMware Horizon View or Citrix XenDesktop.
An article in Tom’s IT Pro, Dell XC Series Powered by Nutanix Ready for Web-Scale, says that three of the Dell XC Series models: XXC720xd-A5, XC720xd-B5 and XC720xd-B7 are “geared specifically for VDI environments”. The article goes on to say that, “The models…are pre-configured for different types of users and virtualization platforms (Citrix, Microsoft, VMware)”.
Floyer’s Wikibon article digs deep into the economics of the Dell vs. VSAN approach – and I suggest reading it in order to get the complete picture. But to summarize, although it costs less money up-front to purchase white boxes + VSAN than the Dell XCs, when evaluating costs over a three-year period – this delta is quickly offset by operating costs and by ongoing software maintenance expense. The Dell “Single Managed Entity” approach is significantly less expensive than white box + VSAN.
Assuming an organization starts with 400 VDI users and increases its user base by 120 desktops a year for two years (rarely do organizations virtualize all of their desktop users up-front), the 3-year TCO for the white box approach is $533,000 vs. only $389,000 for the Dell XC Series solution. This equates to $28 per white box VM vs. $21 per XC Series VM. Additionally, the Super Micro solution requires 36.8 days to deploy vs. just 6.3 days for XC Series.
The article does not specifically address, let alone attempt to quantify, differences in the two solutions in areas such as resiliency, performance or enterprise capabilities. It does, however, discuss the reduced complexity and lower risk of both deployment and support of the Dell XC Series approach.
Floyer concludes, “Wikibon research demonstrates that converged application appliances, correctly implemented, offer significantly lower costs and faster time-to-value for applications in general. Dell and Nutanix have introduced a specific converged application appliance for VDI desktops, provided by a single source, with single sets of updates, a single hand to shake, and a single throat to choke. Wikibon strongly recommends the Dell & Nutanix converged VDI application appliance be included in any RFP for VDI implementation.”
Tips for a Successful Virtual SAN (VSAN) Proof of Concept (POC). 11/14/2014. Cormac Hogan. cormachogan.com.
Is VMware Virtual SAN Production Ready Yet? 11/12/2014. Eiad Al-Aqqad. Virtualization Team.
How I Learned to Stop Worrying and Love Commoditization. 11/08/2014. Peter Wagner. Gigaom. [My comments debate the author]