Facing issue with VMSS allocation of virtual machines in East US region.

Hello Dinesh,

Thank you for reaching out to Microsoft Q&A.

• We understand that your Preprod environment is impacted due to allocation failures when starting or resizing your Virtual Machine Scale Set (VMSS) in the East US region. The error message: Allocation failed We do not have sufficient capacity for the requested VM size in this zone.
• It indicates that Azure currently does not have enough capacity for the requested VM size in the specified zone.
• This happens due to -
  • Regional or zonal capacity constraints.
  • Over constrained requirements (specific zone, proximity placement groups, availability sets).
  • Older VM sizes or large deployments.
• Retry the operation later capacity may become available as resources are freed.
• Change VM size or series Select a size with better availability in East US or consider newer SKUs.
• Avoid pinning to a specific zone if possible. Remove proximity placement groups or availability set constraints.
• Use a different region or zone If East US remains constrained, consider deploying in East US 2 or another region.
• Scale gradually For large deployments, add VMs in smaller batches.
• Check Azure Resource Health Verify if there are capacity issues in East US.
• This is a regional capacity limitation rather than a configuration issue. The quickest resolution is to:
  • Retry later.
  • Switch to a different VM size or region.
• Reference link - https://free.blessedness.top/en-us/troubleshoot/azure/virtual-machines/windows/allocation-failure

Kindly let us know if the above helps or you need further assistance on this issue.

Thanks,
Manish Deshpande.