ARM Template fails due to Availability Set

A.Ali758493 — Wed, 05 Nov 2025 05:35:04 GMT

Hi All,

I am trying to deploy Azure-1FW-3-Interfaces-existing-environment using following ARM template

https://github.com/PaloAltoNetworks/ReferenceArchitectures/tree/master/Azure-1FW-3-interfaces-existing-environment

However, deployment fails due to following error. Availability set created with 'Aligned' SKU and Managed 'YES'

"code": "OperationNotAllowed",
"target": "VMC-fw-001",
"message": "Addition of a VM with managed disks to non-managed Availability Set or addition of a VM with blob based disks to managed Availability Set is not supported. Please create an Availability Set with 'Aligned' SKU in order to add a VM with managed disks to it."
}

Re: ARM Template fails due to Availability Set

A.Ali758493 — Thu, 06 Nov 2025 01:05:05 GMT

I found a solution. Existing script was creating unmanaged disks. Whereas Azure has deprecated it with availability zone.

Therefore In above script if you remove "storageAccountName" "storageAccountExistingRG".

Also under "osDisk" replace "vhd" section with following, (Premium or Standard)

"managedDisk": {

"storageAccountType": "Premium_LRS"

}

topic Re: ARM Template fails due to Availability Set in VM-Series in the Public Cloud

ARM Template fails due to Availability Set

Re: ARM Template fails due to Availability Set