Unable to start VM in South Central US

Jason Scheffelmaer 20 Reputation points Microsoft Employee
2026-04-07T16:04:10.8133333+00:00

Failed to start virtual machine 'VM-name Redacted'. Error: Allocation failed. VM(s) with the following constraints cannot be allocated, because the condition is too restrictive. Please remove some constraints and try again. Constraints applied are: - Subscription Pinning - VM Size

There may be some pinning restrictions that need lifted.

Azure CycleCloud
Azure CycleCloud

A Microsoft tool for creating, managing, operating, and optimizing high-performance computing (HPC) and big compute clusters in Azure.

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Answer accepted by question author
Anonymous
2026-04-07T16:35:54.49+00:00

Hello Jason,

This occurs when the subscription is pinned to a limited set of compute clusters, and the requested VM size is not available (or exhausted) on those pinned clusters. Even if regional capacity exists, Azure cannot place the VM outside the pinned clusters. 

To fix it, we need to remove or modify subscription pinning and for that :

  • Subscription Admin access is required
  • A business justification is necessary

We have reached out to you via Private Message for further assistance if needed.

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  1. Alex Burlachenko 25,120 Reputation points MVP Volunteer Moderator
    2026-04-08T09:20:21.78+00:00

    Jason Scheffelmaer hi ) thx for asks at Q&A platform and stay with us,

    this is just capacity + pinning fighting u, Azure basically saying: cant find hardware that matches ur exact combo

    key part is: Subscription Pinning + VM Size

    so ur pinned to specific hardware/cluster AND asking for a specific size > no capacity there

    nothing is broken, just no room

    I assume the quick ways out could be

    try different region or zone (even same region different zone sometimes works)

    pick another VM size (even close one)

    deallocate and start again later (capacity frees up randomly)

    remove pinning if u dont really need it

    CycleCloud often pins VMs to keep them on same hardware > good for perf, bad when region is full.

    tldr ur over-constrained. relax either pinning or size, or move region

    rgds,

    Alex

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