This integrated and streamlined software package puts the benefits of a virtual desktop infrastructure (VDI) within reach of small business IT.
Many small businesses currently enjoy cost savings as a result of their decision to consolidate an IT infrastructure via server virtualization -- that is, replacing multiple physical servers with software-only "virtual" ones that can co-exist within a single physical server. Another form of virtualization gaining traction and known as VDI (Virtual Desktop Infrastructure) extends the benefits of virtualization out to users' PCs; having employees work off virtual desktops running on a central server means less money spent buying, deploying and maintaining new desktop and laptop computers.
But while server virtualization is a relatively mature technology that's within reach of most small businesses, the same can't currently be said for a VDI. Virtualizing a handful of servers is one thing, but virtualizing dozens, scores or hundreds of individual user desktops -- and doing so with acceptable levels of performance and reliability -- tends to be cost-effective only for larger organizations. It requires pricey specialized hardware and complex software components to manage the interactions between a user's virtual desktop and his or her physical PC.
Figure 1: Citrix VDI-in-a-Box templates let you specify virtual desktop operating parameters for individual users or groups.
Citrix's VDI-in-a-Box 5.0 (which is the result of the company's 2011 acquisition of Kaviza) aims to make VDI feasible for small business IT departments; it combines all the pieces necessary for VDI into an integrated package that can run comfortably on garden-variety server hardware. To be sure, if VDI-in-a-Box actually came in a box it would be labeled "SOME ASSEMBLY REQUIRED", but what's noteworthy is how streamlined that assembly process is and how thoroughly Citrix walks you through it in the form of detailed wizards and copious online documentation (in both written and video form). Indeed, we managed to get a basic, small-scale VDI-in a-Box system up and running in about a day.
VDI-in-a-Box System Requirements
If your small business is currently using virtual servers, chances are you're already using one of the three major hypervisor platforms VDI-in-a-Box 5.0 supports: Citrix's own XenServer (naturally), Microsoft's Hyper-V, and VMWare's VSphere. (Hyper-V support in particular is new to version 5.0.)
VDI-in-a-Box's system requirements depend on several usage variables, most notably how many and what kind of virtual desktops you want to deploy. Those virtual desktops can run either Windows 7 SP1 (Professional or Enterprise, 32- or 64-bit) or Windows XP Professional SP3 (32-bit).
General hardware guidelines for a server running VDI-in-a-Box are six to 10 virtual desktops supported per CPU core and 512 MB to 2GB of RAM needed per virtual desktop. Disk space requirements depend on the size of the OS image(s) used to generate virtual desktops, but 1 TB of space should be enough to comfortably accommodate as many as 50 desktops. (Consult Citrix's VDI-in-a-Box Server Sizing Guide for more detail.)
For our test setup, we installed VDI-in-a-Box on a quad-core 2.9 GHz AMD Phenom II with 12 GB of RAM, and a 1 TB hard disk, using the free version of XenServer 6 as the underlying hypervisor.
The first step to getting VDI-in-a-Box off the ground is to import its VDI manager virtual appliance file into your hypervisor. We used Citrix's XenCenter management console to import the file into XenServer and assign it an IP address with a few mouse clicks.
A few minutes later the VDI-in-a-Box appliance was up and running; and we were able to point a Web browser to its IP address to run the initial setup wizard. This prompts the hypervisor's administrative account credentials and other parameters VDI-in-a-Box needs to operate, such as whether you want to set up a user account database or pull accounts from Active Directory.
VDI-in-a-Box uses grid architecture to provide redundancy (servers are organized into a grid, and all the servers in a grid are functionally identical, so if one dies any of the others act in its place). The first time you set up a VDI-in-a-Box server you're also creating a new grid. You can add another VDI-in-a-Box server to an existing grid, and the first server replicates the data to the new machine for fault tolerance (though we didn't have an opportunity to test this).
After VDI-in-a-Box has been configured, the next step is to import a Windows image that forms the basis for the so-called "golden image" that's used to generate the virtual desktops. Unless you already have an image, this requires creating a new virtual machine in your hypervisor, installing a pristine version of Windows on it (along with hypervisor management tools) and making sure Remote Desktop access is enabled.
Creating Virtual Desktops
When it's time to import the Windows image into VDI-in-a-Box to create the golden image, the software will tell you if your image isn't suitable, and more importantly, why, so you can correct any problems. It then walks you through the multiple steps involved in preparing the golden image for deployment, such as installing the Citrix Desktop Agent, verifying remote connectivity, editing the image with applications, updates, etc. A provided checklist ensures that critical image configuration requirements have been met before VDI-in-a-Box uses it to create a draft copy of the golden image.
Once the golden image draft has been created, you have an opportunity to test the image to make sure it's functioning as intended. This is where we encountered a notable snafu -- we were unable to log into our image due to a licensing error message that turned out to be the result of an expired DLL file. Citrix provided an updated DLL that rectified the issue once we returned to the edit stage and replaced the errant file.
As it turns out, the problem DLL had expired on January 1, 2012, which caused considerable consternation among existing VVDI-in-a-Box users who found their virtual desktops inaccessible the morning of January 2nd This illustrates one of the potential pitfalls of centralized virtual desktops -- a single point of failure caused a bad file to break all the desktops -- but conversely it also demonstrates one of the benefits -- namely, that updates to countless virtual desktops can be propagated easily by applying them to a single master image.
Figure 2: To minimize errors during the image generation process, VDI-in-a-Box presents a checklist of critical configuration items.
After patching and re-testing our image, the final step was creating a template to specify things such as how many virtual desktops would be available (and how many started up in advance), how much RAM they'd be allocated, and whether they'd be able to access local devices such as printers and USB drives. You can create multiple templates that apply to specific users or groups of users.
With our virtual desktops online, we were able to connect to them from a variety of PCs using a Web browser, a Java client, or Citrix Receiver software. Citrix Receiver is available for non-PC platforms as well, and we used it on an iPad to successfully connect to a virtual desktop. (Android devices are capable of the same thing.) While it's hard to make performance judgments about VDI-in-a-Box based on our small-scale setup, we managed to run four functional and responsive Windows 7 desktops on our modest test server.
VDI-in-a-Box is licensed on a concurrent-user basis, so you don't have to purchase licenses for all your users, just enough for those who will use the virtual desktops at a given time. The cost-per-user license is $55 per year annually, or $160 for a perpetual license. Either way, there's an additional (and mandatory) annual charge of $35 for licensed user for "Software Maintenance," which covers product updates and technical support.
To calculate the full cost of a VDI-in-a Box setup, you need to consider not just the aforementioned charges, but also the cost of the hosting server (or servers), the hypervisor software (if any) and finally, volume licensing for Windows. (Volume licensing is the only kind where Microsoft allows running the operating system in a virtual machine.)
Even factoring these attendant costs, it's not hard to envision how a virtual desktop delivered by VDI-in-a-Box might very well ring up for less than the cost of buying and supporting a new PC. (Citrix estimates a cost of $260 to $425 per virtual desktop, though its estimate assumes the desktops are accessed via existing PCs and also doesn't include the recurring software maintenance charges.)
The Bottom Line
Setting up a VDI is far from a trivial undertaking, but VDI-in-a-Box manages to do a very good job of distilling the complexity inherent in the technology down into a very manageable package -- one that a generalist IT manager familiar with imaging and virtualization technology should be comfortable with. Any small business IT department with plans to replace a sizable number of PCs in the near future would do well to give VDI-in-a-Box a close look.
Price: $55 annually or $160 perpetually per concurrent user, plus $35 per concurrent user for software maintenance
Pros: Simplifies the process of creating and managing virtual desktops; runs on generic server hardware; compatible with all major hypervisors.
Cons: Centralization of desktops represents single point of failure; requires volume licensing for Windows OS.
Joseph Moran is a veteran technology writer and co-author of Getting StartED with Windows 7, from Friends of ED.
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