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Comparison: Cloud Compute (EC2 vs Azure VMs)

Category: Cloud Provider Crosswalk Last meaningful update consideration: 2026-07 Scope: AWS EC2 and Azure Virtual Machines. GCP Compute Engine pending — see Security+ hub-style "in progress" note below.

This isn't a "which is better" comparison — if you're on a job, you're on that job's cloud. It's a translation layer for engineers who are fluent in one and need to get productive in the other fast, particularly for interviews where "what's the Azure equivalent of an EC2 instance profile?" is a real question people get asked.

Service Crosswalk

Azure concept Closest AWS concept Where the analogy breaks
Azure Virtual Machine EC2 instance Azure frequently exposes NIC, disk, and public IP as separately managed ARM resources.
VM size Instance type Azure quota is checked against both total regional vCPUs and VM-family vCPUs. SKU availability varies sharply by zone.
Azure Marketplace image Public/Marketplace AMI Publisher/offer/SKU/version URNs are used; image-generation compatibility matters.
Azure Compute Gallery EC2 Image Builder + AMI sharing/copying Gallery separates image definitions from versions and manages regional replication directly.
Managed Disk EBS volume Azure disk SKUs, host caching, bursting, and VM aggregate disk caps create different tuning constraints.
Temporary disk Instance store Not every Azure VM size includes one; Windows pagefile/Linux ephemeral use conventions differ.
Ephemeral OS disk Instance-store-backed root volume / disposable node image Azure explicitly supports an ephemeral OS mode with reimage-oriented lifecycle and no normal stop-deallocate resume.
Availability Zone Availability Zone Broadly equivalent, but zone numbers are subscription-relative physical mappings and should not be treated as universal datacenter IDs.
Availability Set Placement strategy across racks/update domains No clean EC2 equivalent. It is a regional logical grouping below zone-level resilience.
Fault domain Distinct rack/power/network failure domain AWS generally abstracts this rather than exposing an availability-set FD number.
Update domain Maintenance batch No direct EC2 equivalent.
VM Scale Set Auto Scaling Group VMSS is also a compute resource model; Flexible and Uniform orchestration differ more than ASG launch-template variations.
Capacity Reservation EC2 On-Demand Capacity Reservation Close analogy; billing discounts remain separate from capacity reservation.
Reserved VM Instance EC2 Reserved Instance / Savings Plan Billing construct, not a deployed VM and not guaranteed capacity.
Azure Dedicated Host EC2 Dedicated Host Similar purpose; placement/fault-domain and licensing details differ.
Managed Identity IAM role attached through an instance profile A managed identity is an Entra service principal with Azure-managed credentials, then authorized separately through Azure RBAC.
VM extension SSM agent association / cloud-init add-on / guest extension Extensions participate in ARM provisioning state and can fail the deployment.
Resource Group No direct equivalent Closest operational mix is CloudFormation stack + tags + resource grouping, but RG is a first-class lifecycle/RBAC/policy scope.

Migration Notes

  • The resource model is more granular in Azure. An EC2 instance is close to one API object. An Azure VM deployment routinely touches 4-6 separate ARM resources (VM, NIC, subnet reference, disks, optional public IP, optional identity). Deleting the VM resource doesn't clean up the rest — budget for orphan-resource detection from day one.
  • Quota is two-dimensional in Azure. AWS service quotas are mostly discussed per instance family or account-wide On-Demand vCPUs. Azure checks both total regional vCPU quota and per-VM-family regional vCPU quota simultaneously — a deployment can fail on either axis independently.
  • "Stopped" is not "not billing" in Azure. This is the single most common cost surprise for engineers moving from AWS. az vm stop from inside the guest leaves the VM allocated and billed; only az vm deallocate (or the "Stopped (deallocated)" state) actually stops compute charges.
  • VMSS orchestration mode is a one-way door. Choosing Uniform vs. Flexible incorrectly means rebuilding the scale set — there's no equivalent "just change the launch template" escape hatch like ASGs have.

The Interview Answer

"What's the Azure equivalent of an EC2 instance profile?" — A managed identity, but the mechanism is different under the hood: it's backed by an Entra ID service principal, and permissions are granted separately through Azure RBAC role assignments, not baked into the identity object itself the way an instance-profile IAM policy is.

"What's the Azure equivalent of an Auto Scaling Group?" — A VM Scale Set (VMSS), but call out that VMSS is also the compute resource itself (not just a scaling wrapper around existing instances), and that the Flexible vs. Uniform orchestration choice is made once, at creation, and can't be changed later.

See Also