Known issues: VMs on Azure Stack Hub

This article lists known issues for troubleshooting the Azure Stack Hub compute resource provider when working with virtual machines (VMs) and scale sets.

Portal doesn't show correct VM name

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

VM boot diagnostics

• Applicable
  This issue applies to all supported releases.
• Cause
  When you create a new virtual machine (VM), you might see the following error message: 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 you try to start a stop-deallocated virtual machine, you might see the following error message: VM diagnostics Storage account 'diagnosticstorageaccount' not found. Ensure storage account is not deleted. This 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 you create a new virtual machine, you might 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 error indicates that you reached the quota for total cores available to you.
• Remediation
  Ask your operator for an add-on plan with additional quota. Changing the current plan's quota doesn't 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.