Virtual Desktop Infrastructure

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Virtual Desktop Infrastructure

by James G. Barr

Docid: 00021006

Publication Date: 2112

Publication Type: TUTORIAL


Virtual desktop infrastructure (VDI) enables enterprise users to access
their office PCs anytime, anywhere and enables enterprise officials to
establish – and enforce – a standard PC configuration or image. VDI
provides telecommuters or teleworkers with a familiar information
technology (IT) environment, thus enhancing their productivity. Perhaps
most importantly, VDI enables the enterprise IT staff to better control
the remote user experience, propagating application changes from a central
server to the virtual desktop.

Report Contents:

Executive Summary

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In today’s increasingly competitive economic climate, business is
conducted 24×7. Whether working at home on a personal PC or on the road
with a company-supplied laptop or mobile device, business users often
require access to the applications and data that are available at the
office. The COVID-19 pandemic has accelerated this dynamic, transforming millions
of office workers into home office workers, potentially on a permanent


Faulkner Reports
Desktop as a Service Tutorial
VMware Horizon Product

Until not that long ago, the only way to accommodate remote workers was
to copy or download the applications and data they might need to their
local PCs. This process was not only time-consuming but problematic, as
the local PC often features a different operating environment and varying
support. What remote workers really wanted – and needed – was a way to
access their office PC and office application environment anytime,
anywhere from any PC or compatible mobile device.

Virtual desktop infrastructure (VDI) technology allows enterprise users
to do just that. The capability permits:

  • Enterprise officials to establish and enforce a
    standard PC configuration or image, frequently referred to as the
    “golden image.”
  • Teleworkers to access a familiar IT environment.
  • IT staff to:
    • Better control the remote user experience.
    • Propagate application changes from a central server.
    • Isolate business operations and assets and, thus, prevent
      interference or contamination at the local PC or mobile device

As defined by analyst Margaret Rouse, “Virtual desktop infrastructure …
is a desktop virtualization technology wherein a desktop operating system,
typically Microsoft Windows, runs and is managed in a data center. The
virtual desktop image is delivered over a network to an endpoint device,
which allows the user to interact with the operating system and its
applications as if they were running locally.”1

Figure 1 illustrates the operation of a server-based VDI environment.

Figure 1. Depiction of Server-Based Virtual Desktop Infrastructure

Figure 1. Depiction of Server-Based Virtual Desktop Infrastructure



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Virtual desktop infrastructure provides a platform that permits
enterprise users to access their applications and data whether at their
office, at their personal residence, a hotel, a conference center, or even
a satellite office or client site. This dynamic is shown in Figure 2.

Figure 2. Virtual Desktop Infrastructure Elements

Figure 2. Virtual Desktop Infrastructure Elements


Persistent Vs. Non-Persistent

Virtual desktop infrastructure can assume one of two forms: persistent or

As described by Citrix, under the persistent model:

  • “A user is assigned a standardized desktop … the first time they log
  • “Each subsequent time they access the VDI environment, they are
    connected to the same desktop with all of their changes retained in the
    virtual OS image. [This] means they can easily pick up where they left
    off and benefit from extensive personalization of the desktop’s virtual
    apps and settings.”

Under the non-persistent model:

  • “[A user] may be connected to the same desktop every time or to a
    randomized one from the [VDI] pool. In either case, no changes are saved
    upon restarting.
  • “Since nothing is saved once the connection is terminated, IT does not
    have to maintain a large number of customized OS images,” allowing for
    easier administration.

When planning a VDI implementation, “[persistent] VDI … is best for
users that need to interact with virtual desktops exactly as they would
with their physical counterparts.”2

VDI Advantages

Virtual desktop infrastructure enables enterprise users to:

  • Access office PCs whenever and wherever they have access to a PC or
    mobile device and a high-speed Internet connection.
  • Protect critical data, which remains safely housed “at the office,”
    from loss or theft.

Virtual desktop infrastructure enables enterprise IT departments to:

  • Establish and enforce a standard PC configuration, thereby
    streamlining maintenance.
  • Expedite the provisioning of remote workers, thus easing
  • Permit the deployment of cloud-enabled, thin-client PCs, in lieu of
    traditional desktop infrastructure.
  • Elevate the security of user desktops by allowing remote access via
    controlled protocols such as Remote Desktop Protocol (RDP).3
  • Ensure compliance with HIPAA and other security and privacy
    regulations. “VDI provides a fence around how end users can use
    different applications, what data and information is shared with them,
    and where and how it is stored on the [enterprise] network.”4

VDI Disadvantages

Despite its benefits, virtual desktop infrastructure can be:

  • Complex, with traditional VDI platforms requiring a
    variety of products – sourced from a variety of vendors – just to
    function properly.
  • Costly, especially if technical specialists are
    required to manage the VDI environment. Add training and certification
    and expenses can accumulate quickly.5

  • Poor performing

    , when first introduced in the mid 2000s, VDI
    performance was frequently poor when compared to traditional, non-VDI
    systems. While the “gap has closed significantly,” the need for periodic
    performance tuning is indicated.6

Current View

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Cloud-Based VDI

For enterprises seeking to avoid a complicated VDI implementation,
virtual desktop infrastructure is also available as a cloud-based service
known as Desktop-as-a-Service (DaaS). As depicted in Figure 3, DaaS
complements Software, Infrastructure, and Platform as-a-Service.

Prominent DaaS vendors include Amazon, Citrix, Microsoft, and VMware.7

Figure 3. DaaS Complements SaaS, IaaS and PaaS

Figure 3. DaaS Complements SaaS, IaaS and PaaS

Source: Wikimedia Commons

According to HiveIO, maker of an all-in-one, single install VDI platform,
a typical DaaS arrangement would “provide an agreed level of management
for the deployment – usually including everything up to the hypervisor but
potentially even including the desktop and applications – this is where
you get the flexibility to choose what level of help you need and get this
from a single vendor.”8

VDI-Related Issues

When planning a VDI implementation, enterprise officials should consider:

Resource Requirements. A virtual desktop infrastructure
consumes network capacity, server capacity, and storage.

An “Offline” Option. A virtual desktop is useless if the
supporting server or network goes down.

Avoiding an Unnecessary Pre-Cloud Diversion. For an
enterprise looking to ultimately migrate all or most of their operations
to the cloud, implementing VDI can be costly and counterproductive.9

Other Considerations – VDI is not appropriate for all
user groups, including:

  • Those requiring massive processing power.
  • Users needing local storage.
  • People with high-end systems that might feel constrained by less
    functional and flexible systems.


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VDI Use Cases

As reported by Mindsight, VDI is “particularly successful” in serving
five specific user communities:

Shift Workers – “Shift workers do not need a designated
computer, and providing them one adds a significant amount of complexity
and cost.”

Healthcare – “VDI enables the administration team to
customize rules and permissions based on the individual virtual desktop.
This becomes extremely convenient in healthcare settings where privacy is
a concern.”

Educational Institutions – “In a school, students are in
the building during predictable hours and only attend the institution for
a finite amount of time. Plus, students should have strict restrictions on
what they can and cannot do with their school-provided PCs and laptops.”

Users with Multiple PCs – “For one reason or another,
some positions in the business world may require a professional to
regularly work on more than one PC. VDI allows that professional to
consolidate their desktop experience and maintain the same desktop across
both devices.”

Remote Users / Sales / Field Technicians – “Employees on
the road, whether they are simply working remotely, in sales, or field
technicians, need to have a reliable way to access their applications and
tools. VDI offers a secure way to enable anytime, anywhere, and any device
access to a consistent, high-performing desktop experience.”10

The COVID-19 Factor

Virtual desktop infrastructure is proving to be a valuable tool in
negotiating the new IT space created by the COVID-19 pandemic:

  • Helping IT teams support a vast network of home computers suddenly
    re-purposed for business applications.
  • Helping homebound IT users repel new and persistent cyber attacks.
  • Helping enterprise executives achieve the first two objectives without
    exploding their IT and security budgets.

VDI’s security contribution is especially significant. As VDI vendor
HiveIO explains: “Employees working remotely are working outside the
physical and virtual security walls afforded by an office. Old laptops,
lack of current security software, sharing your laptop with your child who
[may be] home schooled and clicking on any banner that blinks, lack of
knowledge and know-how, the list of issues grows by the day. [Enterprises]
are looking to VDI [for a solution].

“VDI provides a fence around your data and your end user. The virtual
desktops, applications, and the OS are all running inside a secure
location. VDI restricts traffic to a well-defined, tightly-controlled
access method. Attackers have a much harder time penetrating into VDI
environments than traditional desktops with their click-bait and other
sleazy mechanisms. VDI has always provided better security – now it is a
must have.”11


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Achieving the promise of virtual desktop
infrastructure, particularly in a large enterprise, requires precision
planning. While each VDI Project Plan is unique, reflecting the
specific requirements of a particular enterprise, there are fourteen basic
plan elements, as detailed in Table 1.

Table 1. VDI Project Plan Elements



Assemble VDI Project Team,
including representatives from each stakeholder group.



Establish VDI Requirements.



Refine VDI Requirements,
using the Request for Information (RFI) vehicle to solicit
vendor intelligence. OPTIONAL



Evaluate Existing Desktop



Devise VDI Transformation
, detailing the migration from real to
virtual desktops.



Identify VDI Pilot
. VDI should be implemented
incrementally, with a “VDI Pilot” providing proof of concept.



Develop VDI Pilot
Implementation Plan
, incorporating:



Quality Assurance Exercises, to verify
successful implementation and operation.



Reversion (or Back Out) Plan, to
permit prior state restoration if the Pilot Plan fails or
adversely affects pilot participants.



User Satisfaction Survey, to validate
proper VDI operation and performance.



Conduct VDI Pilot.



Review Pilot Findings,
to identify “lessons learned” and inform the development of the
VDI Implementation Plan.



Develop VDI Implementation
, incorporating:



Quality Assurance Exercises, to verify
successful implementation and operation.



Reversion (or Back Out) Plan, to
permit prior state restoration if the VDI Plan fails or
adversely affects pilot participants.



User Satisfaction Survey, to validate
proper VDI operation and performance.



Create VDI Service Level
, detailing VDI service expectations and
standard metrics.



Execute VDI Implementation



Monitor VDI Operation and
Assess Service Performance



Upgrade VDI Capabilities and/or Extend


1 Margaret Rouse. “What Is Virtual Desktop Infrastructure?
VDI Explained.” TechTarget. 2020.

2 “What Is Virtual Desktop Infrastructure (VDI)?”

Systems, Inc.


3 “10 Things IT Professionals Need to Know About VDI.”

. 2020.

4 Ibid.

5 Ibid.

6 “What Is Virtual Desktop Infrastructure (VDI)?”

Systems, Inc.


7 “Cloud-Based VDI Virtual Desktop Infrastructure Market
Forecast 2017-2022 Insights Shared in Detailed Report.” WhaTech.
September 14, 2017.

8 “How to Determine If WVD Is the Right Choice for Virtual
Desktops.” HiveIO. 2020.

9 Kim Lindros and Ed Tittel. “Virtual Desktop Infrastructure
Offers Risks and Rewards.” CIO Magazine. December 16, 2013.

10 “Top 5 Use Cases for VDI.” Mindsight. 2018.

11 “10 Things IT Professionals Need to Know About VDI.”

. 2020.

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About the Author

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James G. Barr is a leading business continuity analyst
and business writer with more than 30 years’ IT experience. A member
of “Who’s Who in Finance and Industry,” Mr. Barr has designed, developed,
and deployed business continuity plans for a number of Fortune 500
firms. He is the author of several books, including How to
Succeed in Business BY Really Trying
, a member of Faulkner’s
Advisory Panel, and a senior editor for Faulkner’s Security
Management Practices
. Mr. Barr can be reached via e-mail at

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