Virtual desktop infrastructure (VDI)
In short: VDI runs users' desktops as virtual machines in a data centre or cloud and streams the screen to any device. A broker assigns desktops, a gateway secures access, and pooled images make patching simple. VDI centralises data and management but needs careful sizing for storage, network and user experience.
What VDI is
Virtual desktop infrastructure (VDI) hosts desktop operating systems as VMs on central servers. Users connect from a laptop, thin client, tablet or browser and see a full desktop, but the applications and data stay in the data centre. Only screen images, sound, keyboard and mouse input travel across the network.
The main components
- Connection broker: authenticates the user and decides which desktop they get.
- Gateway: a secure entry point, usually in a DMZ, so remote users connect without a full VPN.
- Display protocol: compresses and sends the screen, such as Microsoft RDP, Citrix HDX, or Blast and PCoIP in Omnissa Horizon (formerly VMware Horizon).
- Desktop pool: a group of VMs built from one master image.
- Profile management: keeps user settings separate from the desktop, for example with FSLogix profile containers.
A related approach is session-based desktops (Remote Desktop Services), where many users share one server OS. This is denser and cheaper per user, but users share resources and some applications do not support it.
Pooled or persistent?
With pooled desktops, a user gets any available VM, and it resets when they log off. You patch one golden image and redeploy, so every desktop is clean and consistent, which also removes malware persistence. Persistent desktops are assigned to one user and keep installed software and changes, at the cost of managing each VM individually.
On-premises VDI or cloud desktops
| Option | Examples | Pros | Cons |
|---|---|---|---|
| On-premises VDI | Citrix, Omnissa Horizon, Microsoft RDS | Full control, data stays on site | Large upfront hardware and skills |
| Desktop as a Service (DaaS) | Azure Virtual Desktop, Windows 365, Amazon WorkSpaces | Pay per user, fast to scale, no hardware | Ongoing cost, depends on internet and cloud region |
Sizing, experience and security
VDI projects often fail on user experience rather than technology. Plan for:
- Boot and login storms: many users signing in at 9 a.m. creates heavy storage load. Flash storage and pre-started VMs help.
- Network latency: aim for low round-trip times to the desktop; video calls and graphics need optimisation or offload.
- Graphics: design and engineering users may need virtual GPUs.
- Licensing: Windows desktop licensing for VDI has specific rules; check them early.
Security benefits are significant. Data never needs to be stored on the user device, so a lost laptop exposes far less. You can block clipboard, drive and printer redirection for sensitive users, require MFA at the gateway and apply central monitoring. It is widely used for contractors, call centres and secure admin workstations.
Tip: run a pilot with real users from each department and measure login time and responsiveness before rolling out. Users judge VDI on how it feels, not on the architecture diagram.
Practice
What does the connection broker do in VDI?
Why do pooled desktops help with security and patching?
What is a login storm?
Key takeaways
- VDI runs desktops as VMs centrally and streams the display to users.
- Key parts: broker, gateway, display protocol, pools and profile management.
- Pooled desktops are easier to patch; persistent desktops keep user changes.
- DaaS options move the infrastructure to the cloud for a per-user fee.
- Plan for login storms, latency and graphics; use VDI to keep data off devices.
Original content written by Mohamed Fayas for FM TecHub. © 2026 FM TecHub. You're welcome to share a link to this page; please don't copy the text elsewhere without permission.