Azure IaaS Migration Guide -- Re-Platform VMware VMs¶

Complete guide to migrating VMware VMs to Azure-native IaaS virtual machines using Azure Migrate, eliminating the VMware dependency entirely.

When to choose re-platform over AVS¶

Re-platforming converts VMware VMs into Azure-native VMs. This eliminates the VMware layer, VMware licensing, and VMware operational overhead. Choose re-platform when:

When to choose AVS instead¶

• VMs depend on VMware-specific features (vSphere APIs, NSX rules, vSAN policies)
• ISV applications certified only on VMware
• Zero application changes required (true lift-and-shift)
• Need to migrate fast with minimal re-engineering

Azure Migrate overview¶

Azure Migrate is Microsoft's free migration platform for discovering, assessing, and migrating VMware workloads to Azure. It provides:

• Discovery: agentless VMware discovery via a lightweight appliance
• Assessment: right-sizing recommendations, cost estimates, readiness analysis
• Replication: continuous replication of VMware VMs to Azure managed disks
• Test migration: non-disruptive migration testing before cutover
• Cutover: final migration with configurable downtime window

Azure Migrate components¶

Phase 1 -- Discovery¶

Deploy the Azure Migrate appliance¶

The Azure Migrate appliance is a lightweight OVA (Open Virtual Appliance) deployed in your VMware environment. It discovers VMs, collects performance data, and enables agentless replication.

# Create Azure Migrate project
az migrate project create \
  --name migrate-vmware-prod \
  --resource-group rg-migration \
  --location eastus2

# Download the appliance OVA from Azure Portal
# Portal > Azure Migrate > Servers, databases and web apps > Discover

Appliance deployment steps:

1. Download the OVA from the Azure Migrate portal
2. Deploy the OVA in your on-premises vCenter
3. Configure the appliance with Azure credentials (register with the Migrate project)
4. Add vCenter Server credentials for discovery
5. Start discovery (scans every 15 minutes)

Appliance resource requirements¶

What discovery collects¶

• VM inventory (name, OS, CPU, memory, disks, network adapters)
• Performance data (CPU utilization, memory utilization, disk IOPS, network throughput)
• Installed applications (Windows: registry-based; Linux: package manager-based)
• SQL Server instances and databases (if present)
• Web applications (IIS, Tomcat, if present)
• Dependencies (agentless via connection data, or agent-based via Dependency Agent)

Phase 2 -- Assessment¶

Create assessment¶

# Create an Azure VM assessment
az migrate assessment create \
  --project-name migrate-vmware-prod \
  --resource-group rg-migration \
  --assessment-name assessment-prod-vms \
  --sizing-criterion "PerformanceBased" \
  --percentile "Percentile95" \
  --time-range "Month" \
  --target-location "eastus2" \
  --offer "MS-AZR-0017P"

Assessment output¶

The assessment provides:

Assessment recommendations¶

Right-sizing and decommission analysis¶

Azure Migrate assessment data frequently reveals that 15--30% of VMs have near-zero CPU/memory utilization. These are candidates for decommission rather than migration. Decommissioning zombie VMs before migration saves significant Azure spend.

Phase 3 -- Replication¶

Agentless replication (recommended)¶

Agentless replication uses the Azure Migrate appliance and VMware vSphere APIs to replicate VMs without installing agents inside the guest OS.

# Enable replication for a discovered VM
# (Typically done via Azure Portal for VM selection)
# Portal > Azure Migrate > Servers > Replicate

How agentless replication works:

1. Initial replication: full disk copy via VMware Changed Block Tracking (CBT)
2. Delta replication: periodic sync of changed blocks (every 5--15 minutes)
3. Sync continues until you trigger cutover
4. At cutover: final sync, VM powered off on-prem, Azure VM powered on

Agent-based replication¶

For VMs that do not support agentless replication (older OS, non-VMware hypervisors), agent-based replication installs the Mobility Service agent inside the guest OS.

Phase 4 -- Test migration¶

Before cutover, run a test migration to validate that the VM works correctly on Azure:

# Test migration creates a test VM in Azure without affecting the source
# Portal > Azure Migrate > Replicated servers > [VM] > Test migration

Test migration checklist:

• VM boots successfully on Azure
• OS and applications start correctly
• Network connectivity to dependent services works
• Storage performance meets requirements (check IOPS/throughput)
• Authentication (AD/LDAP join, Entra ID) works
• Application-level health checks pass
• Monitoring agents (Azure Monitor, Defender) report correctly

Test migrations should use an isolated test VNet to avoid IP conflicts with the production environment. Do not connect the test VNet to production networks.

Phase 5 -- Cutover¶

Cutover process¶

1. Schedule maintenance window: coordinate with application owners
2. Final sync: Azure Migrate performs a final delta replication
3. Power off source VM: stop the on-prem VM to ensure data consistency
4. Complete migration: Azure Migrate finalizes the Azure VM
5. Verify Azure VM: boot, test application health, verify connectivity
6. Update DNS/load balancer: point traffic to the new Azure VM IP
7. Monitor: watch for 24--48 hours before decommissioning on-prem VM

Cutover timing¶

Post-cutover tasks¶

# Verify VM is running
az vm show \
  --name migrated-vm-01 \
  --resource-group rg-migrated-vms \
  --query "powerState"

# Enable Azure Backup
az backup protection enable-for-vm \
  --resource-group rg-backup \
  --vault-name rsv-prod \
  --vm migrated-vm-01 \
  --policy-name daily-backup-policy

# Enable Defender for Cloud
# (Automatic if subscription-level Defender is enabled)

# Install Azure Monitor agent
az vm extension set \
  --name AzureMonitorLinuxAgent \
  --publisher Microsoft.Azure.Monitor \
  --vm-name migrated-vm-01 \
  --resource-group rg-migrated-vms

VM conversion details¶

What changes during migration¶

Driver and agent changes¶

After migration, Azure Migrate automatically:

1. Removes VMware Tools (or marks for removal)
2. Installs the Azure VM Agent (waagent for Linux, WindowsAzureGuestAgent for Windows)
3. Configures Azure accelerated networking drivers
4. Updates SCSI/NVMe drivers for Azure storage

Networking considerations¶

IP address management¶

DNS cutover¶

# Update DNS A record to point to Azure VM private IP
az network private-dns record-set a update \
  --resource-group rg-dns \
  --zone-name contoso.internal \
  --name app-server-01 \
  --set "aRecords[0].ipv4Address=10.20.1.50"

CSA-in-a-Box integration¶

For database and analytics VMs migrated to Azure IaaS, the next step is modernization to PaaS via CSA-in-a-Box:

Migration from Azure IaaS VM to PaaS¶

This two-step approach (VMware to Azure IaaS to PaaS) is often the most practical path for data workloads: get off VMware quickly with Azure Migrate, then modernize to PaaS on Azure timelines.

Related¶

• AVS Migration Guide
• Azure Migrate Tutorial
• Networking Migration
• Storage Migration
• Feature Mapping
• Migration Playbook
• Microsoft Learn: Azure Migrate

Last updated: 2026-04-30 Maintainers: CSA-in-a-Box core team