Citrix VDI-in-a-Box vs XenDesktop – does size matter?

Just in time for the major desktop virtualisation event known as VMworld, Citrix have announced the release of XenDesktop 5.5 as part of their desktop virtualisation trifecta. This latest release is truly an advanced and feature rich VDI solution, but it is not the only VDI offering Citrix has.

Citrix acquired Kaviza in May 2011. Kaviza had developed an interesting technology stack that allowed a range of organisations to deploy a hosted desktop infrastructure using a grid architecture built on standard server hardware. Unlike other virtual desktop infrastructure solutions (such as VMware’s View or Citrix’s XenDesktop), Kaviza’s solution meant that the infrastructure to enable desktop virtualisation could be cheap, readily scaled and more easily administered by those more used to managing desktop environments.

This technology is now Citrix’s VDI-in-a-box solution. Citrix are touting it to the small/medium business market (SMB/SME). Smaller businesses are, without doubt, under pressure to do more with less and are looking for affordable desktop solutions. VDI-in-a-box is specifically geared to address these concerns.

Yet, in the big product release announcement, there is no mention of VDI-in-a-box. Granted along with XenApp, XenClient and XenDesktop this would make four products and ‘quadfecta’ gets some unusual returns in Google. More importantly, VDI-in-a-box is not part of Citrix’s FlexCast pitch: surely unusual for an offering that is intended to enhance the take up of VDI ?

Is it that VDI-in-a-box can only be used by SMBs? Does VDI-in-a-box have no place in a hybrid desktop strategy? Is there a migration path should your small business grow? Does VDI-in-a-box not have a  place in the enterprise? What functions in XenDesktop are not in VDI-in-a-box and of those functions, and what makes them so important for an enterprise?

What is VDI-in-a-box

The Kaviza technology essentially provides a VM appliance that includes:

  • Built-in delivery controller/connection broker
  • Built-in load balancing
  • Built-in desktop provisioning engine
  • Built-in user management
  • Built-in grid engine to deliver high-availability

Kaviza uses this grid architecture to make expansion easy, and at the same time deliver high-availability without requiring externally attached shared storage (e.g., SAN). To expand a Kaviza deployment, you simply load the appliance on additional servers, and add the new servers to the grid by answering two simple questions in the management software. The servers need not be exactly the same type, but do need to be running the same hypervisor. The technology automatically prepares the new servers with the appropriate desktop images, and load balances the desktop workload across the grid. It is important to note that VDI-in-a-box is licensed concurrently.

Such simplicity obviously allows for appeal to the SMB/SME maket segment as we discussed in our previous article Citrix Reach Out for the SME market with Kaviza Aquisition. Yet, we questioned then if the VDI appliance model would be geared solely and only at a single market segment.

While XenDesktop 4 was a complex beast to install, effort was put into XenDesktop 5 to make it more straightforward. XenDesktop 5.5 offers improved ease of management again. Is XenDesktop still a complex product – and what features are worth such complexity?

VDI In a Box Architecture Overview

XenDesktop – not just a single product?

Early versions of XenDesktop suffered from scalability, reliability and simplicity issues. By XenDesktop 5 many of these issues had been addressed: the internal management architecture was re-written, dependency on AD changes were removed, a Machine Creation Service automated VM builds and importantly, there was a new and simplified installation process. There are a number of additional enhancements in the XenDesktop 5.5 as we mentioned on its release.However, even with the new features such as HDX optimisations, the integration with RemoteFX, and the ability to utilise XenServer’s IntelliCache functionality to reduce SAN requirements, the process of architecting and expanding a XenDesktop solution requires you to consider a number of components. The SAN, the Virtual Desktop Hosts, the delivery controllers.But then, a XenDesktop license offers more than simply a VDI service. With XenDesktop you can manage access to hosted desktops sure – running on VMware ESX, on XenServer or Microsoft’s Hyper-V (a feature unavailable so far in VDI-in-a-box). With a XenDesktop license you can also extended to support traditional PCs, or blade devices. With XenDesktop 5.5 you can incorporate Citrix’s personal vDisk technology (based on their RingCube acquisition), as long as your hypervisor platform isn’t Microsoft’s Hyper-V.While VDI-in-a-box supports HDX – XenDesktop 5.5 has improved Adobe Flash redirection, improved video and media redirection and multi-stream ICA allowing for more flexible QoS routing. Moreover, if your end-devices support Windows 7, you’ve full RemoteFX support capabilities, Aero redirection and 3D Pro enhancements. Oh, and if you need to support TWAIN scanner devices – your luck is in: but there are some nice usability features for USB drive redirection in terms of mirroring the way “traditional” desktop environments display USB devices.For many organisations XenDesktop is rarely considered as the only Citrix product deployed. While there is a per concurrent user version, the higher editions are licensed per user or per device. The Enterprise Edition allows the use of XenApp, the higher Platinum comes with Repeater or Access Gateway licenses as well as Password Manager: both Enterprise and Platinum enable you to use the higher Citrix Essentials XenServer features (all be it for the resources in the XenDesktop environment only).XenDesktop is a single product – but purchasing the (more expensive) enterprise features give a a number of features that an organisation can use for deploying and managing a virtualised desktop environment. Example XenDesktop Architecture

Is XenDesktop’s problem that it can’t fit on a box?

Citrix would likely admit that the XenDesktop product was not designed for small desktop deployments (despite there being a 10 user free ‘lite’ edition). To be fair, their XenApp product offered a more cost effective and easy to manage solution to provide applications and desktops to users. With the latest XenApp 6.5 release there are even features to make a Windows 2008R2 desktop appear more like a Windows 7 environment. Still, even with a XenDesktop only implementation,  you still have to manage the XenServer environment. Citrix’s price point does not help either. There was an opportunity for the likes of VMware, Quest, 2x and Ericom to offer useful and more cost effective services. Which they rose to.

That said, the most recent version of XenDesktop is perhaps the most straightforward to install, and  a great deal of work has been done to reduce and ease administration. In a XenServer environment it is arguable that you could host all XenDesktop services on a box. But you would be missing the facility to distribute and manage services beyond that one box. You get some high end remote protocol performance tools sure – but for the majority of virtualised desktops in the enterprise – these features are often unnecessary.

What Cost Complexity?

A major benefit of VDI-in-a-box is that it is readily scalable and definable. Obviously, this is great for small organisations who don’t want complexity.  Complexity costs money. But cost saving isn’t a problem limited to the SMB market.  Reduced complexity and cost is of benefit to any sized organisation, or indeed, to service providers seeking to deliver hosted desktops to their customers.

An SMB/SME would typically be considered between 50-500 users – and lets say that’s “devices” to allow a bit of generosity. Yet, such a definition has little place when considering a desktop virtualisation solution. When scoping what solution to deploy for virtualisation, initial considerations are about how the service provides facilities for users to access applications and data , where the user needs to access those from, and when. Scoping is never about the size of the organisation.

You do not start with “how many users have you got?”

There is perhaps a problem in that VDI-in-a-box is is perhaps too simple. It is interesting to note that while Citrix partners can sell VDI-in-a-Box; there is little sales incentive to market it.

Citrix has an extensive desktop portfolio in terms of features. Perhaps it is better to consider what XenDesktop brings – high-end specifics for multi-media performance, integration with other desktop services… and TWAIN support. It has been stated that XenDesktop and the Kaviza technology will be remain independent. The holy grail of many Citrix Administrators for a Quest-vWorkspace-like convergence of XenDesktop and XenApp is slowly coming but has so far been ruled out for Kaviza.

Citrix have created confusion among partners and customers before with the poisitioning of XenDesktop in respect to the more widely adopted XenApp. The challenge for Citrix is to position their VDI portfolio effectively. At the very least there should be a standardised license plan and migration path from (or to)  the grid and non-grid solutions. There is potential to remove the reduced functionality versions of XenDesktop. Most importantly – to have a license model that allows organisations to make a choice of technology that fits their need, not their size. Can Citrix FlexCast be truly flexible if it ignores the value that having a grid technology can bring not only to the SMB market – but to any sized enterprise?