Known issues: VMs on Azure Stack Hub

You can find known issues for troubleshooting the Azure Stack Hub compute resource provider when working with virtual machines (VM)s and scale sets in this article.

Portal doesn't show correct VM name

  • Applicable
    This issue applies to all releases.
  • Cause
    When viewing details of a VM in the overview blade, the computer name shows as (not available). The display is by design for VMs created from specialized disks/disk snapshots.
  • Remediation
    In the portal select Settings > Properties.
  • Occurrence
    Common

NVv4 VM size on portal

  • Applicable
    This issue applies to Azure Stack Hub release 2002 and later.
  • Cause
    When going through the VM creation experience, you will see the VM size: NV4as_v4. Customers who have the hardware required for the AMD MI25-based Azure Stack Hub GPU preview are able to have a successful VM deployment. All other customers will have a failed VM deployment with this VM size.
  • Remediation
    None.
  • Occurrence
    Common

VM boot diagnostics

  • Applicable
    This issue applies to all supported releases.
  • Cause
    When creating a new virtual machine (VM), the following error might be displayed: Failed to start virtual machine 'vm-name'. Error: Failed to update serial output settings for VM 'vm-name'. The error occurs if you enable boot diagnostics on a VM, but delete your boot diagnostics storage account.
  • Remediation
    Recreate the storage account with the same name you previously used.
  • Occurrence
    Common

VM diagnostics storage account not found

  • Applicable
    This issue applies to all supported releases.
  • Cause
    When trying to start a stop-deallocated virtual machine, the following error might be displayed: VM diagnostics Storage account 'diagnosticstorageaccount' not found. Ensure storage account is not deleted. The error occurs if you attempt to start a VM with boot diagnostics enabled, but the referenced boot diagnostics storage account is deleted.
  • Remediation
    Recreate the storage account with the same name you previously used.
  • Occurrence Common

Consumed compute quota

  • Applicable
    This issue applies to all supported releases.
  • Cause
    When creating a new virtual machine, you may receive an error such as This subscription is at capacity for Total Regional vCPUs on this location. This subscription is using all 50 Total Regional vCPUs available. This indicates that the quota for total cores available to you has been reached.
  • Remediation
    Ask your operator for an add-on plan with additional quota. Changing the current plan's quota will not work or reflect increased quota.
  • Occurrence
    Rare

Virtual machine scale set

  • Applicable
    This issue applies to all supported releases.
  • Cause
    Create failures during patch and update on four-node Azure Stack Hub environments. Creating VMs in an availability set of three fault domains and creating a virtual machine scale set instance fails with a FabricVmPlacementErrorUnsupportedFaultDomainSize error during the update process on a four-node Azure Stack Hub environment.
  • Remediation
    You can create single VMs in an availability set with two fault domains successfully. However, scale set instance creation is still not available during the update process on a four-node Azure Stack Hub deployment.
  • Occurrence
    Rare

Next steps

Learn more about Azure Stack Hub VM features.