What is Start VM on Connect (And Why You Need It)

The Smart Scaler Team
Azure VM starting on user connection

If you’re scaling your AVD environment aggressively (and you should be), there’s one Azure feature you absolutely need: Start VM on Connect.

What Is It?

Start VM on Connect is an Azure feature that automatically starts a deallocated session host when a user tries to connect to it.

In simple terms: users can connect even when all your VMs are turned off. Azure will spin one up for them.

Why Does This Matter?

Without Start VM on Connect, aggressive scaling is risky. If all hosts are deallocated and a user tries to connect, they get an error.

With Start VM on Connect, you can safely:

  • Scale to zero outside business hours
  • Reduce capacity during quiet periods
  • Let the system self-heal when unexpected demand arrives

How Long Does It Take?

Users typically wait 1-2 minutes for a host to start. Not instant, but acceptable for off-hours access.

The experience:

  1. User launches AVD
  2. Azure starts a deallocated host
  3. User connects once it’s ready

Most users find this perfectly acceptable when they understand it.

How to Enable It

  1. Go to your host pool in Azure Portal
  2. Select Properties
  3. Set Start VM on connect to Yes
  4. Save

That’s it. One toggle.

Requirements

  • Windows 10/11 Enterprise multi-session or Windows Server
  • Users need the Desktop Virtualization Power On Contributor role
  • Works with both personal and pooled host pools

Best Practice

Combine Start VM on Connect with a minimum capacity setting:

  • Business hours: Scale based on demand
  • Off-hours: Minimum 0-1 hosts, Start VM on Connect enabled

This gives you maximum savings while ensuring users can always connect.

The Smart Scaler Integration

The Smart Scaler is designed to work with Start VM on Connect. Our schedules can safely scale to zero, knowing that Azure will handle unexpected connections automatically.


Not using Start VM on Connect yet? Enable it today — it takes 30 seconds and unlocks significant savings potential.