Navigating VMware Alternatives for Operational Technology
By Alan Polk, P.E., Technical Execution Leader | Richie Heap, Technical Consultant | Navdeep Saini, IT Consultant
Why OT Teams Are Rethinking VMware
For over two decades, VMware has served as the default hypervisor and dominated virtualization across industries, particularly in operational technology (OT) environments supporting control systems and critical infrastructure. However, since VMware’s acquisition by IT infrastructure giant Broadcom in 2023, the platform has moved away from one-time licensing in favor of cloud services and a subscription-only model. These changes are prompting many OT leaders to reassess whether VMware remains the best fit for their on-premise environments—systems deployed and managed locally, without reliance on cloud infrastructure.
While VMware offers sophisticated features and widespread support, several shifts have made it less aligned with current OT needs.
OT Environment Requirements
OT systems have specific needs that virtualization platforms must support:
- Air-gapped compatibility: Many OT environments require full isolation from the internet to ensure cybersecurity and process stability. Platforms that rely on regular license validation, like VMware under its current structure, may not meet this need.
- Redundancy and continuous availability: Uninterrupted visibility into live processes is essential. VMware supports full VM redundancy (running the same virtual machine on two hosts simultaneously), minimizing disruption during hardware failures. Most alternatives offer only failover (restarting the VM after a failure) which can introduce delays of up to 90 seconds.
- Predictable licensing and lifecycle control: OT systems often remain in service for 5-10 years, where perpetual licensing and stable long-term support are preferred. VMware’s move to subscriptions can complicate lifecycle planning.
These requirements, along with broader strategic considerations, are leading OT teams to explore alternatives better suited to their environments.
Strategic and Technical Considerations for OT Virtualization
When evaluating a virtualization platform, OT teams must weigh both technical capabilities and broader operational realities:
- Licensing and cost models: One-time investment and long-term stability are often preferred over recurring subscription costs that require internet access and periodic renewals.
- Security posture: Linux-based hypervisors typically offer fewer vulnerabilities and don’t require third-party antivirus software, which can slow performance or introduce instability.
- Ease of support: Access to skilled personnel and third-party support can reduce operational risk.
- System architecture and resource demands: OT environments often benefit from virtualization platforms that minimize hardware overhead and avoid additional operating system layers. Simpler, dedicated hypervisors typically deliver better performance on constrained systems.
- Migration complexity: Transitions between platforms can be smooth, particularly when timed with a hardware refresh. Cloning existing VMs and switching over network connections can reduce downtime to minutes. However, successful migration depends on careful planning, especially around BIOS settings, VM compatibility, and avoiding network conflicts during cutover.
These strategic considerations should guide how you assess potential virtualization platforms for your OT environment.
Comparison of Leading Virtualization Platforms
As OT teams evaluate alternatives to VMware, two platforms stand out for their technical capabilities and relevance in industrial environments. Microsoft Hyper-V is a well-established virtualization platform built into Windows Server. It’s widely supported and familiar to many IT teams, especially those already invested in Microsoft infrastructure. Proxmox is a Linux-based, open-source virtualization solution that has gained popularity for its flexibility, low cost, and transparency. It offers clustering, high availability, and full control, appealing to teams that value independence and system hardening.
| Feature | VMware | Microsoft Hyper-V | Proxmox |
| Air-Gap Friendly | Yes, with periodic offline validation (180 days) starting with VCF 9 | Yes, with configuration | Yes |
| Antivirus Required | No | Yes, Server with Desktop Experience (GUI), Microsoft recommends using Windows Defender | No |
| Architecture | Linux-based | Windows-based | Linux-based |
| Cost Model | Subscription only | Perpetual license | Free/open-source + paid support |
| Networking Management | Intuitive | Less intuitive | Comparable to VMware |
| Redundancy (Fault Tolerance) | Full | Failover only | Failover only |
| Security Posture | Strong | Higher risk (Windows-based) | Strong (open source scrutiny) |
| Support Availability | Broad market support | Broad market support | Smaller, niche support |
| System Resource Impact | Low | Moderate – does not necessarily run on Windows; the hypervisor can be installed directly on the server’s h/w (bare-metal) | Low |
| USB Passthrough to VM | Yes (native) | No native block-level passthrough | Yes (USB passthrough) |
Platform Fit Based on Priorities
Your team’s unique priorities will determine which virtualization platform is the best fit. If you:
- Need maximum feature depth and supportability: VMware remains unmatched in advanced capabilities like fault tolerance and complex virtual networking. Its broad vendor ecosystem makes it easier to find third-party support.
- Want Windows integration and wide vendor familiarity: Hyper-V is ideal for Microsoft-centric environments. It offers solid performance and is easy to adopt for teams already familiar with Windows Server infrastructure.
- Prioritize cost, openness, and independence: Proxmox offers a strong alternative for teams able to manage a steeper learning curve. It supports high availability, clustering, and offers transparency through open-source development, making it especially appealing to security-conscious teams.
When to Consider a Switch
The ideal time to evaluate or shift platforms is during a hardware refresh, when infrastructure changes are already planned and risks can be minimized. Platform transitions are typically easier when VMs can be cloned and staged in parallel with current systems, allowing for clean handoff with minimal downtime.
Whether you’re looking to reduce long-term costs, improve system hardening, or adapt to a changing licensing landscape, timing your platform shift strategically can help ensure a smooth transition.
If you’re evaluating options or planning a change, Hargrove Controls & Automation can help you assess your environment and develop a plan that aligns with your goals. Contact us today.
