Desktop Hypervisors in 2015

Four and a half years ago, I wrote an article exploring the competition between Citrix and VMware in the desktop hypervisors space: Citrix and VMware face-off over client hypervisors. Citrix had just released XenDesktop 4.0 Feature Pack 2, which introduced XenClient as a bundled component in XenDesktop. One month earlier, at VMworld, VMware had broken the glass ceiling separating VMware from Citrix with View 4.5.

The 4.5 version of View fulfilled Gartner’s requirements for an enterprise-class, server hosted virtual desktop platform. Along with enterprise essentials, including support for Windows 7, change auditing, role-based administration, and significantly improved scalability, View 4.5 introduced Local Mode, VMware’s extension of View that allowed a hosted desktop image to be run locally on a client hypervisor. This was a big deal at the time; connectivity wasn’t what it is today, and the high cost of meeting the IOPS loads incurred by VDI was a major disincentive to adoption. Client or desktop hypervisors appeared to be an attractive way to deliver a virtual desktop management model without committing to a massive data center investment.

Four years on, IOPS is no longer the challenge it once was, the number of circumstances where connectivity cannot be assumed has diminished considerably, and the hardware cost of server hosted virtual desktops is now substantially below the cost of a comparable desktop PC. Nevertheless, the need for offline support has not diminished. The largely unfounded enthusiasm from business leaders for BYOD remains high. Even as the fallout from the unprecedented Sony megahack continues to send ripples throughout business and government, IT leaders are still being pushed to find ways to accommodate BYOD. VDI and DaaS, while vastly more mature than they were four years ago, are still not suitable for everyone, and the client hypervisor deserves a second look.

VMware has moved on from a client hypervisor–based approach. It dropped View Local Mode from Horizon View 6.0 in favor of Mirage, the containerized desktop solution it acquired with Wanova. View 6.0 added new features, such as expiration, to the policies available in VMware Fusion and VMware Player, making them broadly comparable to the View Local Mode feature set—albeit without the manageability of View.

Where VMware has moved on, Citrix has continued to invest in client hypervisors. Citrix released the Citrix Desktop Player for Mac in January 2014, and XenClient 5.1 in March 2014 with a much expanded hardware compatibility list. Other features added included support for the latest devices using Intel’s fourth-generation Core processors, along with greater scalability across large distributed enterprise environments via roaming support with the XenClient Synchronizer management service (This Virtualization Practice white paper by Joe Jessen explores using XenClient as part of larger desktop strategy.) The big difference between XenClient and Desktop Player for Mac is the hypervisor. Apple jealously guards access to its platform and does not permit the use of a Type 1 (bare metal) hypervisor, requiring all virtualization to be done through a Type 2 hypervisor running on top of OS X. While Type 2 hypervisors are inherently less efficient than Type 1s, they can be installed just as any other application and do not require a destructive install like a Type 1 hypervisor does.

Prior to the release of DesktopPlayer, the only support that Citrix offered Mac users was through XenApp and XenDesktop. The introduction of DesktopPlayer gave Mac users a local mode option for the first time. Now Mac users have access to the same Windows desktop images that can be run on a Windows PC using XenClient. Rather than start from scratch, Citrix chose to OEM Oracle’s VirtualBox as a quick fix. There is good business sense to this approach, as Apple’s momentum in the enterprise is growing, but most Mac users in the enterprise still need to run Windows apps. Both Google and Facebook have found Apple’s enterprise support so lacking that they have developed their own Mac management tools. Considering Apple as part of the border mobile ecosystem (pretty much every Mac in the enterprise is a laptop), it makes sense for Citrix to establish a foothold in the border Mac app delivery market. It was better for Citrix to buy its way in than wait until it could build something in-house.

Citrix has laid hints about a forthcoming DesktopPlayer for Windows since 2013, and at the Synergy conference in May last year, it announced that a tech preview would be available “soon.” Nine months later, you can still sign up for access to the tech preview here, and there are indications that it will be available ahead of Synergy 2015.

For all this progress, I can’t help but think that Citrix is coming to the Type 2 hypervisor market very late in the game, especially considering that former Citrix CTO and XenSource founder Ian Pratt was working on Hosted Xen, a Type 2 hypervisor that ran on Windows, OS X, and Linux, as far back as 2009.