Virtualization: A Vital Building Block for Modern OT & ICS Environments
Virtualization has become a transformative force in Operational Technology (OT) and Industrial Control Systems (ICS). Initially adopted to reduce physical hardware footprint and better utilize powerful modern servers, virtualization has now evolved to support entire OT environments, including virtual PLCs (vPLCs).
Today, virtualization is no longer just an IT convenience, it is a core enabler of availability, resilience, and cybersecurity in modern industrial architecture. When designed correctly, virtualized OT environments align strongly with ISA/IEC 62443 requirements, particularly those related to system availability, integrity, and secure operations.
Executive Summary
- Virtualization is now widely adopted in OT/ICS environments, including virtual PLC deployments with SIL certifications
- It significantly improves availability, reduces downtime, and simplifies backup and recovery
- Virtualization directly supports ISA/IEC 62443 FR#7 – Resource Availability, along with several other foundational requirements
- Risks such as flat networks and weak hypervisor management must be mitigated through proper segmentation and security controls
At CS4 by DTS Solution, we leverage secure, clustered virtual infrastructure to deliver resilient OT cybersecurity services
Why Virtualization Matters in OT & ICS
1. High Availability Through Server Clustering
Traditional OT deployments often rely on single physical servers, creating single points of failure. Virtualization eliminates this limitation by enabling OT workloads to run on server clusters, providing:
- Automatic failover
- Redundant execution
- Minimal disruption during hardware failures
This capability aligns directly with ISA/IEC 62443 -FR#7 (Resource Availability) and is essential for safety-critical and continuous-process industries.
2. Simplified Backup & Rapid Restoration
Virtual machines are stored as logical files, enabling:
- Fast, full-system backups
- Rapid recovery after failures or cyber incidents
- Reduced Mean Time to Recovery (MTTR)
This dramatically improves operational continuity and supports both availability and integrity requirements in OT environments.
3. Optimized Use of OT Hardware Resources
Virtualization allows multiple OT systems to coexist efficiently on shared infrastructure, including:
- SCADA servers
- Historians
- Engineering workstations
- Application servers
- Virtual PLCs
Key benefits include:
- Lower CAPEX
- Reduced rack space
- Lower power and cooling requirements
- Improved lifecycle management
These efficiencies are now a design expectation, not a luxury, in modern ICS architectures.
Cybersecurity Challenges & Risks of Virtualization in OT
While virtualization provides significant benefits, it also introduces new cybersecurity risks, particularly when OT security principles are not enforced.
Common challenges include:
- Lateral movement due to flat or poorly segmented networks
- Full OT environment compromise through vCenter or hypervisor access
- Weak role-based access control (RBAC)
- Insufficient visibility and monitoring of virtual assets
In OT, one compromised virtualization layer can impact multiple critical systems simultaneously, increasing both cyber and safety risk.
This reinforces the importance of secure-by-design virtual architecture.
IEC 62443 Security Requirements Mapping for Virtualized OT Architectures
Virtualization Feature | OT Benefit or Mitigation | IEC 62443 FR | Applicable SR |
Server clustering & HA | Continuous operation, automatic failover | FR 7 – Resource Availability | SR 7.2 – Resource management |
VM snapshot & backup | Rapid restoration, reduced downtime | FR 7 – Resource Availability | SR 7.3 – Control system backup SR 7.4 – Recovery |
Virtual PLC deployment | Redundant, scalable control logic | FR 7 – Resource Availability | SR 7.2 – Resource management |
Hypervisor / vCenter hardening | Prevents total system compromise | FR 5 – Restrict Data Flow | SR 5.1 – Network segmentation SR 5.2 – Zone boundary protection |
VLAN segmentation | Limits lateral movement | FR 5 – Restricted Data Flow | SR 5.1 – Network segmentation |
Secure VM migration | Protects data in motion | FR 3 – System Integrity | SR 3.1 – Communication integrity |
Centralized logging | Enhanced detection & monitoring | FR 6 – Timely response to events | SR 6.2 – Continuous monitoring |
How CS4 by DTS Solution Enables Secure Virtualization in OT
At CS4 by DTS Solution, we design a secure, resilient virtualized architecture to deliver:
- High availability and fault tolerance
- Strong segmentation and secure hypervisor management
- Full alignment with ISA/IEC 62443 system requirements
- Optimized resource utilization
- Hardened designs for critical industrial sectors
Our mission is clear:
Deliver modern OT virtualization with secure design, robust implementation, and reliable long-term operation.