A typical control room hides a rack of lightly loaded servers, each running one SCADA role and each needing its own spares and patches. Running those roles as virtual machines on a few hosts cuts hardware, power and recovery time together.
Virtual machines let several operating systems share one physical server. For control systems, that means fewer boxes, faster restores and easier upgrades, if the design respects real time and security needs.
What Is SCADA Virtualization?
SCADA virtualization is the practice of running SCADA servers, historians, engineering stations and thin client hosts as virtual machines on a hypervisor instead of on separate physical computers. The SCADA software itself behaves as before, as described in how SCADA systems work.
Yokogawa explains that one hypervisor can run several operating system instances of different types, which allows server consolidation. That reduces floor space, power and spare parts.
The shift fits the modern generation of networked SCADA described in 4 generations of SCADA architecture. Virtual machines are simply files that can be copied, backed up and restored.
Most major SCADA vendors now publish supported virtual platforms and settings. Always check that list before choosing a hypervisor version.
Hypervisor Types
Runs directly on server hardware.
Runs on top of a desktop operating system.
Two or more hosts share storage and restart failed VMs.
Mirror VM runs in lockstep on a second host.
Yokogawa notes that hardware assisted virtualization, such as Intel VT x and AMD V, runs much faster than software emulation. Enable it in the server BIOS.
It also warns that the host needs memory for itself, so an 8 GB host may give only about 4 GB to guest systems.
How a Virtual SCADA Platform Is Built
Map virtual switches to the physical SCADA network switches so control traffic never mixes with office traffic. Use VLANs and dedicated NICs.
Storage should be redundant, often using mirrored or RAID parity arrays. A single disk failure must never stop the control room.
7 Smart SCADA Virtualization Steps
USB licence keys and serial COM ports are the classic problems after moving to VMs. Network licence servers and Ethernet serial converters solve both.
The hypervisor becomes a high value target, so follow SCADA network security and zero trust principles for its management interfaces.
Host Sizing Formula
Hosts needed = ceiling(Total RAM ÷ Usable RAM per host) + 1 spare
Example:
8 VMs at 16 GB each = 128 GB, host overhead 16 GB per host
Hosts with 128 GB each give 112 GB usable
128 ÷ 112 rounds up to 2, plus 1 spare = 3 hosts
Do the same check for CPU cores and storage, then use the largest result. Keep CPU use below about 60 percent at normal load.
Plan for growth of at least 30 percent over the system life.
Host Sizing Calculator
If one VM is larger than a single host can hold, redesign it, since HA cannot restart it anywhere.
- Fewer physical servers.
- Fast restore from snapshots and backups.
- Easy test copies of production.
- Hardware refresh without reinstalling.
- USB and serial hardware links.
- New skills for maintenance staff.
- Hypervisor security and patching.
- Vendor support limits.
Virtualization also simplifies later upgrades, a key point in migration and obsolescence management.
Yokogawa SCADA Virtualization PDF
HMI and SCADA Virtualization Video
SCADA Virtualization FAQ
Related Articles
- How SCADA Systems Work
- SCADA Redundancy Architecture
- Network Switches for SCADA and DCS
- 10 Enterprise SCADA Tips
- SCADA Network Security
External References
- Virtualization Application Note, Yokogawa
- Virtual SCADA Servers, Yokogawa America
- Hypervisor, Wikipedia
What We Learn Today
- SCADA virtualization consolidates servers onto hypervisor hosts.
- Type 1 clusters with HA and N+1 sizing protect availability.
- Plan licences, serial links, time sync and hypervisor security.