Azure VM AllocationFailed - Insufficient capacity in region when starting VM

Question

Hello,

I am trying to start my Azure Virtual Machine (viona-mvp-h100), but it fails with the following error:

AllocationFailed - We do not have sufficient capacity for the requested VM size in this region.

The VM was previously created successfully, but now it cannot start due to capacity constraints.

Details:

• VM Name: viona-mvp-h100
• Error Code: AllocationFailed
• Provisioning State: Failed
• OS: Linux
• Operation: Start VM

I would like to understand:

1. Is this a temporary regional capacity issue?
2. Is there a way to request capacity for this specific VM size?
3. How long do such capacity constraints usually last?

Thank you for your assistance.

Answer 1

Hello Hassine,

Thank you for reaching out Q/A. The error message you're receiving: "AllocationFailed - We do not have sufficient capacity for the requested VM size in this region" means that Azure currently does not have enough free capacity in the region you’re trying to start your VM (viona-mvp-h100) for that particular VM size.

This issue is not related to your VM configuration or subscription limits. It occurs when the underlying Azure infrastructure cannot allocate the required physical resources at the time of the start operation. Such situations are more common with large or specialized VM types or during periods of elevated regional demand.

Please note that regional capacity constraints are typically temporary; however, Azure does not provide a guaranteed resolution timeframe.

You can consider the following approaches:

• If your region supports multiple availability zones, attempting to start or deploy the VM in another zone may succeed.
• Selecting an alternative VM size with comparable specifications that currently has available capacity can resolve the issue.
• Azure On-demand Capacity Reservations allow you to reserve compute capacity in advance to improve deployment reliability and predictability. Documentation: https://learn.microsoft.com/en-us/azure/virtual-machines/capacity-reservation-overview Please note that Capacity Reservations must be created while capacity is available; they do not create new capacity if the region is already fully allocated.

If the VM is part of an availability set:

• Stop (deallocate) all VMs in the availability set. Navigate to Resource groups > Resources > Virtual Machines > Stop.
• After stopping, filter by availability set, select all applicable VMs, and click Start. This ensures a new allocation attempt is run and Azure can select a cluster with sufficient capacity.

For detailed information, please check: https://learn.microsoft.com/en-us/troubleshoot/azure/virtual-machines/windows/allocation-failure

Hope this helps! Please let me know if you have any queries.