The Why of VDI

If you don't know where you're going, you will wind up somewhere else."
      – Yogi Berra

Despite the huge industry fervor around VDI, virtualizing desktops is much more challenging than virtualizing data centers and encompasses both technical hurdles and a less apparent ROI. Also factoring in are hundreds or thousands of users with differing expectations and perceptions. Yet, the most common question I get from organizations considering a virtual desktop deployment is whether to use VMware View or Citrix XenDesktop. Some even kick off their VDI efforts with a Proof-of-Concept comparing the two connection brokers side by side. Taking a product-centric approach to VDI, however, is likely to create unnecessary difficulties and can potentially result in project stall or outright failure.

The Why of VDI: Objectives

Approaching VDI on a strategic level is necessary for a successful enterprise deployment. The reasons for virtualizing desktops in the first place need to be identified and, where appropriate, quantified. This includes evaluation of the anticipated impact that virtual desktops will have on both business and IT objectives as well as the part they will play in the overall enterprise desktop strategy and in the data center virtualization/ITaaS plans. The architecture to best enable achievement of the prioritized objectives can then be designed. At this point, individual product choices will often be self-evident. When they are not, product comparisons and TCO studies can be performed, but always within the context of optimizing the desired architecture.

The versatility, agility and scalability of virtual desktops enable use cases that in many cases exceed what is practical in a physical desktop environment. That being said, common reasons for implementing VDI include: management, security, disaster recovery, workforce mobility/user productivity, contractors, BYOPC initiatives, green initiatives, remote office computing, acquisition assimilation, voice and video convergence, and reduced costs.

The How of VDI: Architecture

We ideally want to design a virtual desktop architecture that will optimally support the organization’s objectives for  virtual desktops as well as factor in existing environmental variables, staffing capabilities and budget. Paramount to the type of architecture requried  is the scope of the initiative along with requirements around availability, redundancy, security and performance. And rather than limiting preparations to a virtual desktop, embracing the concept of an “enterprise desktop” can incorporate physical or hybrid situations as appropriate.

A detailed assessment of the existing desktop and data center environments should include not only tools that identify desktops, applications, resource utilization and usage patterns, but also interviews with different user groups and IT personnel. Among other components, the information collected should encompass applications, user categories, use cases, data center environment, PC/Laptop environment, remote office components and management structure.

After gathering the infrastructure and user information, the environment can then be designed including elements such as scope, management/security, storage, network, compute, persistent vs. nonpersistent desktops, application delivery, availability, scalability, client devices, etc.

The What of VDI: Products


Comparing and contrasting product attributes, features and costs in isolation can lead to conclusions unsupportive of the ultimate architecture and organizational objectives. Products need to be mapped to their ability to support the desired architecture not only in isolation, but with some indication of their interfaces and interactions with each other as well as with appropriate infrastructure functionality outside the scope of the proposed VDI environment. These mappings can include attributes such as staff familiarity, integration with the management platform, compatibility with the planned security construct, etc. The following table shows some of the variables requiring consideration for effective product selection.


IOPs & other storage requirements

User acceptance of change

Existing computing devices

Capacity requirements

Unified communications

Tablets, Smart Phones


Data center  integration

User experience

User personalization


User perceptions

App requirements

Use cases

BYOPC initiative

App categorization

User categorization

Contractor requirements

Graphic load

Security requirements

Acquisition requirements

App virtualization

Compliance requirements

Remote access requirements

App delivery

Disaster recovery requirements

Budget limitations

App performance

Availability /Redundancy

Off-line usage


Avoiding VDI Stall

Determining the objectives behind a virtual desktop initiative adds clarity, achieves funding and provides guidelines for architecture design. Requirements or SLAs around performance, security, availability, regulatory compliance, user productivity, etc. will, in many cases, dictate which products best support the optimal architecture for achieving the desired objectives. This enables far better decisions and, ultimately, a much higher probability of project success.


Author Note

This post is composed of edited excerpts from my recent white paper, The Why of VDI.


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One Response to The Why of VDI

  1. Jayson Dills says:

    Jayson Dills

    Very good blog post.Many thanks again. Awesome.

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