VMware to Hyper-V Migration in Windows Admin Center: Agentless & Fast

Microsoft has quietly rolled out a public preview of a new VM Conversion tool inside Windows Admin Center that aims to make VMware to Hyper‑V migration straightforward, agentless, and low‑risk for organizations of all sizes. The extension promises quick setup (Microsoft says you can begin converting VMs in under five minutes), agentless discovery of vCenter inventories, bulk conversions of up to ten VMs at a time, support for both Windows and Linux guests, and a two‑phase replication workflow that uses change‑block tracking (CBT) to minimize downtime during cutover. For IT teams wrestling with platform consolidation, license optimization, or hybrid cloud onboarding, this tool changes the migration calculus — but it also carries important caveats that must be understood before planning a production migration.

Background​

The Windows Admin Center (WAC) ecosystem has steadily expanded beyond simple server management into practical migration and hybrid management scenarios. The new VM Conversion extension builds on that trajectory by embedding a VMware→Hyper‑V V2V workflow directly into WAC, eliminating the need to deploy separate appliances or install guest agents in many migration scenarios. The tool targets on‑premises migrations — it’s presented as a path to modernize infrastructure while preserving on‑prem requirements, and as a potential stepping stone to cloud services if desired.
Microsoft positions the extension as a lightweight, supported option for smaller and medium organizations in particular, emphasizing minimal infrastructure prerequisites and integrated prechecks to reduce surprise failures. Under the hood, the workflow relies on VMware tooling (VDDK) and PowerCLI to interact with vCenter/ESXi environments, while the destination side leverages Hyper‑V on Windows Server hosts managed through WAC.

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What the VM Conversion tool does (at a glance)​

• Agentless discovery of vCenter inventories — no guest agent required for initial discovery and synchronization.
• Two‑phase replication: initial online seeding followed by a final delta replication after source shutdown to reduce cutover time.
• Change‑block tracking (CBT) usage for efficient delta replication.
• Bulk selection: select and synchronize up to 10 VMs in a batch.
• OS‑agnostic support: migrations for both Windows and a list of supported Linux distributions (Linux guests typically require Hyper‑V integration/kernel drivers for reliable post‑migration boot).
• Boot type mapping: BIOS → Hyper‑V Generation 1, UEFI → Generation 2.
• Multi‑disk support: all attached virtual disks (OS, data, application disks) are handled together.
• Destination format: VHDX files created on the destination are dynamically expanding (thin‑provisioned) by default.

These capabilities are designed to reduce manual configuration work and to make cutovers predictable when prechecks pass and prerequisites are met.

How the conversion workflow actually works​

Discovery and prechecks​

After installing the VM Conversion extension in Windows Admin Center v2 (GA), administrators connect WAC to a vCenter endpoint using FQDN and credentials. The extension performs an agentless discovery of VMs, then runs a battery of prechecks before any data transfer begins. These prechecks validate critical items such as:

• Presence of active snapshots (these block initial sync).
• Source VM disk layout and types.
• Boot configuration (BIOS vs UEFI).
• Destination storage availability and free space.
• Memory requirements and compatibility with Hyper‑V host settings.

By surfacing issues early, the tool aims to reduce conversion failures at cutover time.

Initial seeding (online replication)​

The tool performs an initial replication — a full copy of the VM data — while the source VM remains online. This seeding phase copies used blocks to a destination folder (VHDX creation) and attempts to minimize service disruption to running workloads.

Delta replication and cutover​

Once the initial seeding completes, the tool captures changes since the seed using CBT mechanisms. A final delta replication occurs after the administrator authorizes cutover and the source VM is powered off. This two‑phase approach shortens the final downtime window to roughly the time required to transfer the delta set and import the VM into Hyper‑V.

Import and configuration​

On the destination, the tool creates a Hyper‑V VM, configures generation (1 or 2) based on detected boot type, attaches migrated VHDX files, and applies basic settings. For Windows guests this often works seamlessly; for Linux guests, preinstalled Hyper‑V integration drivers (or Linux Integration Services) can be required to ensure the VM boots properly and networking functions as expected.

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Prerequisites and technical checklist​

Before any migration, several platform prerequisites must be met on the Windows Admin Center gateway and the destination Hyper‑V hosts:

• Windows Admin Center v2 (GA) installed and used as the gateway.
• Hyper‑V role installed on the Windows Server host used as the migration target.
• PowerCLI module installed on the WAC gateway (Install‑Module VMware.PowerCLI).
• VMware Virtual Disk Development Kit (VDDK) (specific version requirements apply — confirm the exact VDDK version required for your environment).
• Visual C++ Redistributable packages installed on the WAC gateway.
• vCenter/ESXi versions supported (vCenter 6.x or higher in most documented previews).
• Ensure no active VMware snapshots exist for VMs to be migrated.
• For Linux guests: Hyper‑V drivers/integration components installed pre‑migration for reliable boot.

Administrators should verify the exact versions of PowerCLI and VDDK required by the extension prior to running a migration because mismatched versions are a common source of failure.

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Verification of key claims and what the numbers mean​

Microsoft’s messaging emphasizes speed and low friction: the claim that you can “begin converting virtual machines in under five minutes” is accurate in the context of installation and initial configuration — the extension integrates into WAC and can be installed quickly. That five‑minute figure refers to getting the tool ready to use, not to the total time required to migrate a VM. The actual time to migrate a VM depends on:

• VM disk size and the amount of used data.
• Network throughput between vCenter datastore/ESXi hosts and the WAC gateway (or wherever synchronization data is placed).
• Storage performance on the destination Hyper‑V host.
• The size of the CBT delta at cutover.

The extension reduces downtime by seeding a full copy while the VM runs and then applying only the deltas for cutover. However, minimal downtime is a relative promise — even with CBT, cutover time can range from seconds for low‑change VMs to minutes or longer for high‑transaction databases or write‑heavy workloads that generate large deltas during the seeding window. Teams must measure delta size and throughput in a test migration before relying on a short outage window for critical production systems.

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Strengths: Why this matters for Windows environments​

• Integrated experience: Embedding migration inside Windows Admin Center removes a management tool boundary; administrators can discover, migrate, and then manage migrated VMs from the same console.
• Agentless discovery: For many environments, avoiding guest‑side agents during discovery and initial sync is a meaningful operational simplification and reduces change control overhead.
• OS‑agnostic support: Supporting both Windows and Linux guests broadens applicability for mixed environments.
• Preservation of boot config and IP options: Automatic mapping of BIOS/UEFI to Hyper‑V generation and options to preserve static IP settings reduce post‑migration remediation.
• Bulk migration capability: Selecting up to 10 VMs for synchronization reduces manual overhead for application tiers and multi‑VM services.
• No additional license cost for the tool itself (it’s provided as a WAC extension), which can make platform consolidation more attractive from a TCO perspective.

These strengths make the tool attractive to organizations that prefer Microsoft‑native solutions and want to bring workloads closer to Windows Server/Hyper‑V or plan phased migration strategies to hybrid cloud.

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Limitations and risks to plan for​

• Prerequisite complexity: Despite being “lightweight,” the tool requires specific external components — PowerCLI, a compatible VDDK, and Visual C++ dependencies. Misconfigured prerequisites are the top cause of failed migrations in early trials.
• Snapshot sensitivity: Active VMware snapshots block initial sync. Removing snapshots can be safe but must be coordinated with app owners.
• Linux guest caveats: Linux VMs often require preinstalled Hyper‑V integration drivers. If those drivers aren’t present or compatible, the migrated VM may fail to boot or have networking issues.
• Thin‑provisioned VHDX destination: The default creation of dynamically expanding VHDX files is space‑efficient but may not match organizational storage policies that expect fixed disks; admins should plan post‑migration conversion steps if fixed disks are required.
• Final downtime variance: The “minimal downtime” benefit depends on delta size and network speed. High‑change workloads remain challenging to migrate without extended outages or application‑level replication strategies.
• No automatic removal of VMware Tools: After migration, VMware Tools are not automatically uninstalled; leaving them in place can cause confusion and requires manual cleanup.
• Unsupported features and edge cases: Some configurations, specialized hardware pass‑through, or vendor‑specific integrations may not translate automatically to Hyper‑V and will require manual remediation.

These limitations underline the importance of performing thorough test migrations and establishing a rollback plan.

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How this compares to existing approaches​

• System Center Virtual Machine Manager (SCVMM) and other Microsoft migration paths have long offered V2V capabilities; recent SCVMM updates improved conversion speed and large‑disk support. The WAC VM Conversion extension is aimed at administrators who prefer a modern, browser‑based management plane rather than the heavier SCVMM stack.
• Third‑party tools and older utilities (including legacy converters from virtualization vendors) provide alternative migration workflows. The new WAC extension differentiates by being free, agentless for discovery, and tightly integrated with Windows Server management tools.
• For large datacenter projects or complex conversions (thousands of VMs, clustered shared storage, or heavy‑transaction databases), organizations may still prefer established, dedicated migration products or staged “replatform and refactor” approaches because they offer more granular controls, scheduling, and enterprise‑grade reporting.

In short, the WAC extension is positioned as the simplest, Microsoft‑native route for many migration projects — especially SMBs and smaller datacenter consolidation efforts — while larger enterprises will weigh it alongside SCVMM and specialized third‑party solutions.

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Practical migration plan and best practices​

Below is a high‑level checklist and recommended sequence for production migrations using the VM Conversion extension.

• Inventory and discovery
• Catalogue VMs to migrate by application, dependency, and change profile.
• Identify mission‑critical services and schedule maintenance windows.
• Environment preparation
• Ensure WAC v2 GA is installed and up to date.
• Install PowerCLI and confirm version compatibility.
• Download and stage the required VDDK version on the WAC gateway.
• Install required Visual C++ redistributables on the WAC gateway.
• Confirm target Hyper‑V hosts have adequate CPU, memory, and storage.
• Test conversions
• Pick representative VMs (small, medium, large, Linux, Windows).
• Run the extension’s prechecks and address any flagged issues.
• Measure initial seed duration, delta sizes, and cutover times.
• Validate guest boot, device drivers, and networking post‑migration.
• Network and storage performance tuning
• Ensure sufficient bandwidth on the replication path.
• Consider temporary storage placement (fast, local SSD) to accelerate copy and import stages.
• Production migration runbook
• Document exact cutover steps, including snapshot removal, final delta sync, source power off, and Hyper‑V VM validation.
• Assign roles (operator, application owner, DBA) and rollback criteria.
• Plan post‑migration tasks: fix MAC addresses, uninstall VMware Tools, convert thin VHDX to fixed if required.
• Post‑migration validation
• Run application and integration smoke tests.
• Validate backups and monitoring for the migrated VMs.
• Archive pre‑migration configuration snapshots in case of later audits.

Following this sequence converts uncertainty into predictable, measurable steps and reduces the chance of an unexpected failure during a production cutover.

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Troubleshooting and common gotchas​

• If the initial synchronization fails, check for active snapshots on the source VM and confirm VDDK/PowerCLI versions.
• If a migrated Linux VM fails to boot, verify the presence and compatibility of Hyper‑V integration drivers and check kernel messages in the console for missing devices.
• If delta replication is unexpectedly large, identify high‑write processes (databases, logging, backups) and consider quiescing or freezing writes during seeding where possible.
• Storage space errors on the destination often stem from assumptions about thin provisioning; confirm actual used size versus provisioned size before starting the sync.
• Performance bottlenecks can show in WAC logs and the VMConversion_log.txt located on the WAC gateway — collect logs early when escalating issues.

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Security, compliance, and operational governance​

Migration projects must not only move bits and boot disks — they must preserve security posture and compliance controls. Key considerations include:

• Credential management: The WAC gateway stores credentials to access vCenter during migration; follow organizational secrets‑management policies and limit scope of accounts used.
• Network segmentation: Ensure replication traffic traverses secure, dedicated channels and does not expose sensitive data across untrusted networks.
• Audit trail: Maintain migration logs for compliance and change tracking; the WAC extension writes logs that should be collected and retained according to policy.
• Hardening destination VMs: Post‑migration, confirm endpoint protection, encryption at rest, and other controls are applied exactly as on source VMs.
• Regulatory constraints: For workloads constrained by data residency or certification, ensure that the move to Hyper‑V hosts does not violate contractual or regulatory requirements.

These governance items are often overlooked in technical pilots but are crucial for enterprise adoption.

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Who should consider this tool — and who should not​

• Consider the VM Conversion extension if:
• You manage on‑premises VMware workloads and want a Microsoft‑native path to Hyper‑V.
• You are an SMB or a team charged with consolidating a limited number of VMs.
• You prefer an integrated, GUI‑driven workflow inside Windows Admin Center.
• Avoid or defer using the tool if:
• You need to migrate thousands of VMs with complex cross‑dependencies and require enterprise orchestration, scheduling, or reporting features that specialized migration suites provide.
• You manage ultra‑high‑availability or zero‑downtime services where even brief cutovers are unacceptable without application‑level replication.
• Your environment uses exotic hardware passthrough or vendor‑specific guest integrations that the tool cannot translate.

Selecting the right migration tooling comes down to matching scope and complexity to tool capabilities.

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What to watch next (roadmap and missing pieces)​

Microsoft indicates continued development of the VM Conversion extension. Potential areas where the tool could expand value include:

• Cluster and scale improvements for large‑scale datacenter migrations.
• Azure connectivity for direct migrations into Azure or integration with Azure Migrate workflows.
• Azure Arc integration for unified hybrid management of migrated servers.
• Automated post‑migration remediation (driver installs, removal of VMware Tools, network policy translation).
• Support for additional VDDK versions and deeper ESXi cluster features.

Administrators planning larger projects should monitor the extension’s release notes and update cadence to capture new capabilities and fixes.

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Conclusion​

The VM Conversion extension for Windows Admin Center delivers an attractive, Microsoft‑native option for many VMware→Hyper‑V migration scenarios. By combining agentless discovery, prechecks, CBT‑based two‑phase replication, and integrated management inside WAC, it materially lowers the barrier to entry for on‑premises platform consolidation. The promise of quick setup and reduced downtime is real — but it comes with practical caveats: prerequisite dependencies, the need for driver compatibility on Linux guests, reliance on CBT and network performance for cutover duration, and the requirement to validate results thoroughly in test runs.
For small and medium organizations or for targeted application migrations, the extension can significantly shorten project timelines and reduce complexity. For enterprise‑scale programs or workloads with stringent uptime requirements, the extension should be evaluated as one viable tool in a broader migration toolbox, accompanied by pilots, performance measurements, and careful operational runbooks. Meticulous testing, clear rollback plans, and attention to post‑migration remediation will be the difference between a smooth platform transition and costly service disruption.

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Source: BetaNews Microsoft previews tool to convert virtual machines from VMware to Hyper-V