{"id":5006,"date":"2013-05-10T18:29:41","date_gmt":"2013-05-10T16:29:41","guid":{"rendered":"https:\/\/ingmarverheij.com\/?p=5006"},"modified":"2013-05-19T13:03:48","modified_gmt":"2013-05-19T11:03:48","slug":"virtual-desktop-word-bingo-stop-using-vdi","status":"publish","type":"post","link":"https:\/\/ingmarverheij.com\/en\/virtual-desktop-word-bingo-stop-using-vdi\/","title":{"rendered":"Virtual desktop word bingo (stop using VDI)"},"content":{"rendered":"

I have developed a strong aversion against the term \u201cVDI\u201d. Basically because customers don\u2019t understand what VDI means, caused by the simple fact that the people who explain this to the customers (the people in IT) don\u2019t understand it either.<\/p>\n

The term VDI is roughly 7 years old. Back then we presumed it was the right term to use, and maybe it was. But time has changed and I strongly believe we are ready for some change.<\/p>\n

Are you ready for some virtual desktop word bingo?<\/i><\/p>\n

<\/p>\n

Virtual Desktop Infrastructure<\/span><\/h1>\n

VPCC<\/span><\/h4>\n

I remember the first VDI implementation I came across roughly 7 years ago, the NEC VirtualPC Center (VPCC)<\/a>. Being one of the first implementations the solution wasn\u2019t mature enough to implement on a large scale, but the name described exactly what it did. VPCC virtualized the PC, ran a desktop operating system and provided access to that machine via a remoting protocol like ICA or RDP (I really can\u2019t remember). And that\u2019s exactly what we\u2019re referring to if we\u2019re talking about VDI, a virtualized desktop operating system<\/i> that users can access from a different location. VPCC quickly dropped off my radar and I forgot all about it, until a few years ago: VDI was a hype. What changed in the mean time? Some improvements on the hypervisor, broker and remoting protocol. And \u201cone more thing\u201d\u2026 marketing got involved.<\/p>\n

 <\/p>\n

\u00a0Desktop<\/h4>\n

The problem with the abbreviation VDI is the word desktop. <\/i>In the abbreviation VDI we\u2019re referring to is the desktop operating system (OS),<\/i> while most people have another association with the word desktop<\/i>: the background image with shortcuts introduced in Microsoft Windows 95<\/a> (okay Windows 3.0 but no one called it a desktop back then). As a result we\u2019re talking about two completely different things; a desktop OS and a background image.<\/p>\n

Customers are asking for a VDI, \u201cI want a VDI\u201d, while they actually want to access a desktop: a background image with icons.<\/i><\/p>\n

When I\u2019m talking about a desktop I\u2019m talking about a background with shortcuts. A \u201cdesktop\u201d computer doesn\u2019t exist, either it\u2019s a workstation (a solid brick on your desk) or it\u2019s a laptop (a mobile device). Using the word desktop when referring to a computer is too confusing. As a generic term for both a workstation and a laptop we could use \u201cpersonal computer<\/a> or PC\u201d instead.<\/p>\n

 <\/p>\n

<\/h3>\n

Citrix XenApp and <\/span>Citrix XenDesktop<\/span><\/h1>\n

Citrix has two products in their offering that provide access to remote applications and desktops, Citrix XenApp and Citrix XenDesktop. It\u2019s good to understand the similarities and differences.<\/p>\n

 <\/p>\n

Client\/server model<\/span><\/h4>\n

The client\/server model by Gartner describes different models for application delivery. There is an assumption that running an application requires three components: the data, the application itself and its presentation.<\/p>\n

If the application runs on your workstation and the data is on the server it\u2019s called \u201cdistributed data management\u201d, you can compare this with running Microsoft Word on your computer while the document is stored on a server.<\/p>\n

Now imagine you view your desktop via a remoting protocol like VNC<\/a>: the computer now acts as a VNC \u201cserver\u201d and presents the content on the local screen and<\/i> on the VNC \u201cclient\u201d. That\u2019s distributed presentation.<\/p>\n

\"Gartner<\/a><\/p>\n

 <\/p>\n

<\/h4>\n

Citrix XenApp<\/span><\/h4>\n

In 2007 Citrix renamed their most important (commercial) product from Presentation Server<\/strong> to XenApp<\/strong>. From a marketing perspective that made sense, but not from a functional (or logical) perspective. Citrix XenApp is an implementation of local\/distributed presentation: it runs the application on the server and the result is presented on the screen of the client. This is also known as \u201cpresentation virtualization\u201d.<\/p>\n

Nonetheless some clever guys at Citrix figured the name XenApp <\/strong>would be better than Presentation Server, to fit in the new Xen naming strategy. I you want to sell a new product XenDesktop<\/strong>, the name XenApp\u00a0<\/strong>makes sense.<\/p>\n

\u201cIf you ask me, Citrix complicated the virtual-desktop-word-bingo game.\u201d<\/p><\/blockquote>\n

90% of the customers think that if you want to access applications from a datacenter you need XenApp and if you want a desktop you need XenDesktop. While in reality both products provide access to both.<\/p>\n

\"Citrix<\/a>\"Citrix<\/a><\/p>\n

I wrote about this in an earlier article<\/a>.<\/i><\/p>\n

Beside some technical differences (IMA vs FMA, more<\/a>) the main difference is that XenApp provides access to a multi-user execution environment<\/i> while XenDesktop provides access to a single-user execution environment<\/i>.<\/p>\n

\"XenApp<\/a><\/p>\n

<\/h3>\n

 <\/p>\n

Back to VDI<\/span><\/h1>\n

\u201cI\u2019m sorry Ingmar, but why is VDI a problem? We managed so far.\u201d<\/em><\/p><\/blockquote>\n

Let me explain with an example, a discussion between a customer<\/span><\/strong><\/span> and an IT guy<\/span><\/strong><\/span>.<\/i><\/p>\n

Hi IT guy! I want to access my applications anytime and anywhere.
I want my applications to run close to my applications\u2019 servers for the best performance and security\u2026
\u2026from a safe and reliable environment (a datacenter).The environment needs to be scalable, flexible, etc.<\/span><\/span><\/p>\n

Sure, we can do that. With Citrix XenApp we can provide you secure
access to your applications from every location at any time. <\/span><\/span><\/p>\n

Great! I want the ability to run some VDI\u2019s as well.<\/span><\/span><\/p>\n

(the customer read about VDI in magazines, websites and discussed it on the golf course)<\/i><\/p>\n

VDI\u2019s? You want to access desktops anytime and anywhere?<\/span><\/span><\/p>\n

Indeed, I need XenDesktop<\/b><\/span><\/span><\/p>\n

(he also saw the XenDesktop offering of Citrix)<\/i><\/p>\n

You want to access a desktop anytime and anywhere, a background image with shortcuts on it?<\/span><\/span><\/p>\n

Exactly! I want to run VDI\u2019s<\/span><\/span><\/p>\n

I can provide you access to a desktop anytime and anywhere via Citrix XenApp<\/span><\/span><\/p>\n

Not XenApp. XenApp<\/span> is for app<\/span>lications, XenDesktop<\/span> is for desktops<\/span><\/span><\/span><\/p>\n

(the customer has a point here)<\/i><\/p>\n

 <\/p>\n

\u201cSee, that\u2019s what I don\u2019t like about the term VDI. The term VDI is interpreted as a desktop\u201d<\/p>\n

 <\/p><\/blockquote>\n

<\/h3>\n

Terminologies<\/span><\/h1>\n

VDI is not the only term we\u2019re using for virtual desktop environments, we tend to use a whole bunch of them to describe nearly the same. Understanding the meaning of a term allows you to explain it to your customer. If you don\u2019t fully comprehend a definition, how can you explain this to a customer effectively?<\/p>\n

 <\/p>\n

Execution platform<\/b> is an environment where applications are executed (or computed). An applications does not run, it is executed by a computer. Resources like the processor, memory and disk of the computer are used to run the processes (and threads) of the application. An execution platform where resources are used by one user is called a single user execution platform (SEP) while an execution platform where resources are shared by multiple users is called a multiuser execution platform (MEP).<\/p>\n

 <\/p>\n

Server Based Computing (SBC) <\/b>is one of the oldest terms, it describes the technology to share resources on a server to run applications or desktops. Microsoft Remote Desktop Services (previously Terminal Services) enables a machine running a Windows Server operating system to share its resources with multiple users, a multiuser execution platform. Citrix XenApp improves the functionality, security, flexibility and performance in a SBC environment.<\/p>\n

 <\/p>\n

Virtual desktop \/ application<\/b> is used to refer to a desktop or application that runs in a virtualized environment. What it doesn\u2019t tell is what type of virtualization is referred to. It could be 1) the computer hosting the desktop \/ application is \u201cvirtualized\u201d or 2) the desktop \/ application runs on a computer hosted on another location or, in case of an application, 3) the application is encapsulated in an isolated execution (called application virtualization<\/a>)?<\/p>\n

When a computer is \u201cvirtualized\u201d we usually refer to virtualizing a computer using a hypervisor like Citrix XenServer (or VMware ESX \/ Microsoft Hyper-V). But we might as well refer to presentation virtualization: the desktop \/ application is executed on a different computer (for instance in a datacenter) while the user\u2019s computer shows the GUI of the application.<\/p>\n

Virtual<\/i><\/b>: \u201cnot physically existing as such but made by software to appear to be so\u201d<\/i><\/p>\n

Virtual<\/em> is a word that can be explained quite broad and is interpreted freely to describe complex matters in a simple way. Basically what we\u2019re saying is \u201cwe\u2019re applying some virtual magic<\/i> and now it\u2019s safer \/ better \/ faster \/ more interoperable<\/a>. There\u2019s no way we can explain what we\u2019re actually doing\u201d.<\/p>\n

 <\/p>\n

Virtual shared \/ private \/ hosted desktop <\/b>are commonly used terms to describe where a desktop is located.<\/p>\n