Virtual Desktop Infrastructure (VDI) – Complete Detailed Guide

What is VDI?

Virtual Desktop Infrastructure (VDI) is a technology that hosts desktop operating systems (such as Windows 10/11 or Linux) on centralized servers. Instead of running the operating system on each user's physical computer, it runs inside Virtual Machines (VMs) located in a data centre or private cloud.

Users connect to these virtual desktops over the network using a VDI client or a web browser.

Unlike Desktop as a Service (DaaS), where the cloud provider manages most of the infrastructure, VDI is typically deployed and managed by an organization's own IT team. The organization is responsible for the servers, storage, networking, virtualization platform, security, backups, and maintenance.

How VDI Works

                      Users
         ┌──────────┬──────────┬──────────┐
         │ Desktop  │ Laptop   │ Thin     │
         │ PC       │          │ Client   │
         └────┬─────┴────┬─────┴────┬─────┘
              │          │          │
              └──────────┼──────────┘
                         │
                 Remote Display Protocol
               (RDP / PCoIP / HDX / Blast)
                         │
                ┌────────────────────┐
                │ Connection Broker  │
                └─────────┬──────────┘
                          │
                 ┌────────┴─────────┐
                 │ Hypervisor       │
                 └────────┬─────────┘
                          │
         ┌────────────────┼────────────────┐
         │                │                │
      VM-01            VM-02           VM-03
    Windows 11       Windows 11      Windows 11
         │                │                │
         └────────────────┼────────────────┘
                          │
               Shared Storage (SAN/NAS)

The user's keyboard, mouse, and display information travel across the network, while applications and data remain on the server.

Main Components of VDI

1. Physical Servers

These powerful servers host the virtual machines.

Example specifications:

2. Hypervisor

A hypervisor creates and manages virtual machines.

Common hypervisors:

• VMware ESXi

• Microsoft Hyper-V

• Nutanix AHV

• Citrix Hypervisor

• Proxmox VE

Responsibilities:

• Create VMs

• Allocate CPU and RAM

• Manage storage

• Handle snapshots

• Support live migration

3. Connection Broker

The broker authenticates users and assigns them a desktop.

Responsibilities:

• User authentication

• VM assignment

• Load balancing

• Session management

• Reconnection after disconnects

Examples:

• VMware Horizon Connection Server

• Citrix Delivery Controller

• Microsoft Remote Desktop Connection Broker

4. Virtual Desktop Machines

Each virtual machine contains:

• Windows 11

• Linux

• Installed applications

• User profile

• Security software

Example:

VM
-------------
Windows 11
8 GB RAM
4 vCPU
Office
Chrome

5. Shared Storage

All VMs store their virtual disks on shared storage.

Common options:

• SAN

• NAS

• Azure Stack storage

• VMware vSAN

• NetApp

• Dell EMC PowerStore

6. Active Directory / Identity Service

Handles:

• User authentication

• Group policies

• Password policies

• Access permissions

Modern deployments often integrate:

• Microsoft Entra ID

• Active Directory

• LDAP

7. Profile Management

Stores:

• Desktop settings

• Documents

• Browser favourites

• Application settings

Common tools:

• FSLogix

• Citrix Profile Management

• VMware Dynamic Environment Manager

Types of VDI

1. Persistent VDI

Each user gets a dedicated VM.

User A
   │
   ▼
Windows VM A

Always the same VM

Advantages:

• Personalised desktop

• Software can be installed

• Ideal for developers and engineers

Disadvantages:

• Higher storage usage

• Higher management overhead

2. Non-Persistent VDI

Users receive a fresh VM every login.

Login

↓

Temporary Desktop

↓

Logout

↓

Desktop Reset

Advantages:

• Easier to maintain

• Lower storage requirements

• Consistent desktop experience

Best suited for:

• Call centres

• Schools

• Hospitals

• Shift workers

How to Configure VDI

The example below uses VMware Horizon concepts, but the overall process is similar for Citrix and Microsoft-based VDI solutions.

Step 1 – Prepare the Infrastructure

Example:

Step 2 – Install the Hypervisor

Install your chosen hypervisor on each server.

Tasks:

• Configure management network

• Set storage locations

• Create virtual switches

• Join servers to the virtualization cluster

Step 3 – Configure Shared Storage

Example:

Storage
----------------
VDI-Datastore
5 TB SSD

Store:

• VM disks

• Templates

• Snapshots

Step 4 – Install Active Directory

Create:

• Domain

• Users

• Security groups

• Group Policies (GPOs)

Example groups:

HR Users
Finance Users
IT Users
Sales Users

Step 5 – Install the Connection Broker

The broker:

• Authenticates users

• Assigns desktops

• Tracks active sessions

Step 6 – Create a Golden (Master) Image

Install:

• Windows 11 Enterprise

• Microsoft 365

• Chrome

• Antivirus

• Company software

• Latest Windows updates

Optimise the image:

• Remove unnecessary applications

• Disable unwanted services

• Configure power settings

This image becomes the template for all desktops.

Step 7 – Create a Desktop Pool

Desktop pools define how VMs are delivered.

Example:

Pool Name

Office Users

Desktop Type

Non-Persistent

VM Count

50

Options:

• Persistent

• Non-persistent

• Manual assignment

• Automatic assignment

Step 8 – Provision Virtual Machines

Example VM:

The VDI platform clones the required number of desktops from the golden image.

Step 9 – Configure Profile Management

Example with FSLogix:

User logs in

↓

Profile Container Loaded

↓

Desktop Appears

↓

Changes Saved

↓

User Logs Out

This preserves user settings while using non-persistent desktops.

Step 10 – Install Applications

Deploy:

• Microsoft Office

• Teams

• Chrome

• ERP software

• Accounting software

• CAD software (if required)

Methods include:

• Image-based installation

• Application virtualization

• Central software deployment tools

Step 11 – Configure Security

Enable:

• Multi-factor authentication (MFA)

• Network segmentation

• Disk encryption

• Endpoint protection

• Firewall rules

• Least-privilege access

• Session timeout policies

Step 12 – Configure Load Balancing

Distribute users across servers.

Example:

Server 1

25 Users

Server 2

25 Users

This improves performance and resilience.

Step 13 – Configure Backups

Protect:

• Golden image

• User profiles

• Shared storage

• Configuration databases

• Connection broker

Regularly test restoration procedures.

Step 14 – Test the Environment

Verify:

1. User login

2. Desktop launch

3. Application functionality

4. Printing

5. File access

6. USB redirection (if permitted)

7. Audio and video quality

8. Performance under load

Example: 100-User VDI Deployment

Advantages of VDI

• Centralised desktop management.

• Stronger data security because data stays in the data centre.

• Easier software deployment and updates.

• Supports remote and hybrid work.

• Fast recovery from hardware failures.

• Consistent user experience.

• Better compliance and auditing.

Disadvantages of VDI

• High upfront investment in servers, storage, and licensing.

• Requires skilled IT staff to deploy and manage.

• Performance depends on sufficient server resources and network capacity.

• Storage and licensing costs can grow quickly with large deployments.

• Complex to design for high availability and disaster recovery.

VDI Login Process

User
   │
   ▼
Open VDI Client
   │
   ▼
Enter Username + Password
   │
   ▼
Multi-Factor Authentication
   │
   ▼
Connection Broker
   │
   ▼
Desktop Pool
   │
   ▼
Assigned Virtual Machine
   │
   ▼
Windows Desktop Loads
   │
   ▼
Applications Start
   │
   ▼
User Works Normally
   │
   ▼
Logout
   │
   ▼
Session Ends

DaaS vs VDI

In summary, VDI offers greater control, customisation, and data governance, but it requires significantly more planning, infrastructure, and operational expertise than DaaS. It is commonly chosen by organisations with strict security, compliance, or performance requirements.