We have been early and big fans of SCADA virtualization for servers and workstations. Not for the server
consultation consolidation benefits that drive most IT virtualization projects. Control systems have a surprisingly small number of servers and workstations so server consultation consolidation (spell check fail) is not a huge benefit. Instead the ability to recover, roll back and test are the key benefits for virtualization in control systems.
Another benefit of virtualization that is not getting much play is the physical-to-virtual feature that allows a vendor, or asset owner, to quickly recreate the environment for support or testing.
Vendor support for virtualization is coming in two flavors. Applications like OPC servers, historians and third party HMI are being deployed on virtual machines by customers and integrators. The vendor does ‘not support’ virtualization per se, but the vendor doesn’t not support customers who chose to deploy on virtual machines.
The other flavor is ICS vendors who typically deploy the system and offer virtualization as a deployment option. We first saw this with AREVA back last summer. We just learned that ABB’s 800xA is now available on virtual machines. (HT: Stephan Beirer of GAI Netconsult in Germany)
There are three ABB SCADA virtualization documents posted:
- 800xA Server Node Virtualization with VMware ESX – This is the most detailed document.
- 800xA Product Update
- A Brochure for a 4.5 day Workshop on 800xA Virtualization
The ABB documents focus on the server consolidation benefits. For example the Product Update states, “A mid sized system using the most common parts of 800xA can be installed on two servers, having similar performance as a system built in the conventional way.” They then give the tag, controller and user limits based on their conservative testing. More from the Product Update.
Virtualization is a new technology in the field of process automation. The verification that has been made in system type test environment has shown good results, and is performance wise even beyond a system built in the conventional way. Still, however, implementing virtualization in a production plant may reveal challenges we can not be fully prepared for.
To mitigate this, SCADA virtualization is made available using the “managed introduction” procedure, i.e. a TSA is required (Temporary Sales Authorization). A TSA is primarily required for production systems using virtualization. Engineering systems as well as internal test-and-learn and demo systems may be set up without having an approved TSA.
The TSA is required for the virtualized system to be assured support coverage.
The ABB document in the first link is more ambitious. It discusses putting all of the primary servers on one ESX and all of the secondary on the second ESX, while leaving the clients as physical systems. There is much better server consolidation in this approach, and we will try to clarify the discrepancy between the two documents.
ABB has also tested up to 30 operational clients / HMI and up to 3 Engineering Workstations on an ESX. The HMI / EWS are good candidates for virtualization because they have relatively low resource utilization and larger number of systems. Spinning up a new HMI should be trivial with virtualization.
Backup and recovery is addressed briefly on pages 17-18 from an operational / how to do it standpoint.
We believe there is a great opportunity for ICS vendors to promote the non-server consolidation benefits of virtualization to a much greater degree to their customers’ benefits. The community harps on availability as the key security goal, for good reason. Virtualization dramatically speeds recovery and facilitates testing and rollback — all important factors to availability.
Congratulations to ABB and others for starting down this path. Now just crow a bit more about it and get customers to maximize the benefits.
Image by The Planet