Azure IaaS Migration: Azure Service Manager to Azure Resource Manager

by | Mar 16, 2021 | Cloud

The first Azure IaaS offering (or infrastructure as a service) utilized Azure Service Manager (ASM) for the administration of virtual machines. However, in 2014, Microsoft introduced IaaS on Azure Resource Manager (ARM) and has focused on building feature rich capabilities. In February of 2020, Microsoft moved to begin the decommissioning of the use of ASM for new builds. VMs built and still managed with ASM are considered “Classic” builds and an Azure IaaS migration will soon be required.

Retirement, Migration, and ARM

Microsoft has notified organizations that still maintain Classic VMs with ASM that this functionality will retire on March 1, 2023. What does that mean to you? Prior to retirement, all Classic VMs will need to be migrated to the ARM platform or they will be deleted. Dates to note: 

  • February 28, 2020: customers who didn’t utilize IaaS VMs through ASM in the month of February 2020 can no longer create VMs (classic). 
  • March 1, 2023: customers will no longer be able to start IaaS VMs by using ASM. Any that are still running or allocated will be stopped and deallocated. 
  • March 1, 2023: subscriptions that are not migrated to Azure Resource Manager will be informed regarding timelines for deleting any remaining VMs (classic). 

While March 2023 seems a long way away, planning and testing should start today. Microsoft sent notifications out in February and September of 2020 listing impacted machines. If you didn’t receive an email, or just want to confirm what is in your environment, there are tools available. These tools will allow you to search for and report on Classic VMs within your environment. 

Planning Your Migration 

Planning is essential as outage windows may be required during the migration process. Start with listing all VMs, storage accounts and applications. Ask yourself, “Is Azure ExpressRoute used, how many VNets exist, are 3rd parties impacted?” You also need to take some time to understand the features and compatibilities between ASM and ARM. If you have a mixed environment of ASM and ARM, what is the integration path and the key preparation tasks? If possible, build a lab to test and understand timing and probable hiccups. 

Peters & Associates is available to partner with your team to review the configurations and benefits of moving to ARM.  Our Cloud solutions and project teams can help prepare the plan, perform testing and be at your side during the production migration. 

If you would like more information on Azure IaaS migration, please contact us at