PaaS Azure VMWare AVS

Demystifying Azure VMware Solution: From Implementation to Workload Migration – Part 5

Migrating to Azure VMware Solution Using vMotion: A Zero-Downtime Approach

Introduction

When migrating workloads to Azure VMware Solution (AVS), minimizing application disruption is a top priority—especially for mission-critical systems. Among the various methods available, VMware HCX vMotion stands out for its ability to move virtual machines live and without downtime, maintaining application availability and reducing business risk.

This post focuses solely on the vMotion migration method with VMware HCX, detailing how to plan, configure, and execute live migrations from your on-premises VMware environment to AVS. Whether you’re transitioning a handful of critical VMs or scaling up to migrate production workloads, vMotion enables a seamless, zero-interruption path to the cloud.

HCX vMotion Migrations

HCX vMotion migrations

Why Use vMotion for AVS Migration?

VMware HCX vMotion enables the live migration of running VMs from on-premises infrastructure to AVS without needing to power them off. Key benefits include:

  • Zero downtime for end users and services
  • No need to re-IP or reconfigure applications
  • Minimal cutover planning
  • Maintains stateful memory and CPU usage during transit

This method is ideal for applications that cannot tolerate downtime or when tight maintenance windows are in place.

Pre-Migration Planning

Environment Assessment

Start by evaluating which workloads are eligible for vMotion:

  • VM hardware version must be compatible with AVS (v13 or higher recommended).
  • Ensure that VMware Tools are up-to-date.
  • Validate that VM configurations are free of incompatible devices (e.g., USB passthrough).

Use tools like RVTools or vRealize Operations to inventory and assess VMs.

Network and Connectivity Readiness

  • A low-latency connection (ideally <100 ms RTT) between on-prem and AVS is crucial. ExpressRoute is recommended.
  • HCX Interconnect and Network Extension appliances must be deployed and paired.
  • Ensure Layer 2 network segments are extended to AVS if retaining existing IPs.

Step-by-Step: Performing vMotion with VMware HCX

Step 1: Deploy and Configure HCX

In Azure:

  1. Navigate to your AVS Private Cloud in the Azure Portal.
  2. Under VMware HCX, click Deploy HCX Manager and follow the wizard.
  3. Once deployed, download the HCX Connector OVA for on-prem deployment.

Or use Bicep to deploy it

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// Parameters for HCX deployment
@description('Name of the AVS Private Cloud')
param avsPrivateCloudName string = 'MyPrivateCloud'

@description('Name of the HCX Enterprise Site')
param hcxSiteName string = 'MyHCXSite'

// Deploy HCX Enterprise Site in AVS Private Cloud
resource avsPrivateCloud 'Microsoft.AVS/privateClouds@2023-09-01' existing = {
  name: avsPrivateCloudName
}

resource hcxDeployment 'Microsoft.AVS/privateClouds/hcxEnterpriseSites@2023-09-01' = {
  parent: avsPrivateCloud
  name: hcxSiteName
  properties: {
    activationKey: 'xxxxx-xxxxxx-xxxxx'
  }
}

On-Premises:

  1. Deploy the HCX Connector OVA into your on-prem vCenter Server.
  2. Activate using the license key provided via the AVS HCX Enterprise entitlement.
  3. Pair the on-prem HCX Connector with the AVS HCX Cloud Manager.
  4. Set up Compute Profiles, Network Profiles, and a Service Mesh to connect both sites.

Step 2: Prepare for vMotion Migration

Before starting a vMotion migration:

  • Extend the VM’s network to AVS via HCX Network Extension if you wish to retain IP addresses.
  • Ensure the VMware vMotion port group is reachable between on-prem and AVS HCX Interconnect appliances.
  • Confirm sufficient resources are available in AVS (CPU/RAM) to accommodate incoming VMs.

Step 3: Execute the vMotion Migration

  1. Log in to the on-premises vCenter HCX plugin.
  2. Navigate to Migration and select Migrate Virtual Machines.
  3. Choose vMotion as the migration type.
  4. Select the VMs to migrate, the destination cluster in AVS, and the destination datastore (typically vSAN).
  5. Optionally, assign tags or change folder locations.
  6. Click Go to initiate the live migration.

During this process, the VM remains online and continues to serve traffic. Once the memory and CPU state are synchronized to AVS, the VM is automatically switched over in a matter of seconds.

Ensuring Success: Best Practices for vMotion

Optimize for Performance

  • Avoid scheduling large vMotion jobs during production peak hours.
  • Monitor throughput and latency using HCX Dashboard and vCenter Performance Charts.

Secure and Verify Migration

  • All vMotion traffic is tunneled through HCX Interconnect appliances using TLS encryption.
  • Validate post-migration health with:
    • VM console access
    • Application response checks
    • Updated monitoring integrations

Conclusion

Using VMware HCX vMotion to migrate workloads to Azure VMware Solution offers a highly efficient, non-disruptive approach—especially for systems where even a brief outage is unacceptable. With the right planning, connectivity, and tooling, live migration becomes a routine part of your modernization strategy, not a risky gamble.

By focusing on vMotion, organizations can:

  • Protect business continuity
  • Avoid costly downtime
  • Transition to AVS with greater confidence

After migration, administrators should validate system behavior, update documentation, and begin monitoring workloads through Azure Monitor or VMware vRealize Operations.

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