More with less, fewer, and smaller
Virtualization: Controlling your PC population
Virtualization is a technology that allows running two or more operating systems side-by-side on just one PC or server, and it is rapidly being adopted in the industrial world. While the word “virtualization” is simply another term for abstraction, in practice it allows engineers to save cost, reduce footprint, and consolidate systems in ways that were not previously possible.
Deploying virtualization allows multiple “virtual machines,” each running its own operating system and application, to function at the same time on a single physical machine. Virtualization achieves this while guaranteeing that a given virtual machine gets exactly the amount of resources required to do its job, and ensuring any issues with one virtual machine won’t impact another. This type of consolidation reduces the need for multiple machines and maximizes the use of hardware resources.
By improving hardware utilization, plants are able to cut down on the number of physical computers they require, which has a direct correlation with the footprint of a control system.
When it comes to a discussion of virtualization as it relates to an industrial control system, it is important to understand the true meaning of the term “footprint.” In addition to the physical space occupied by servers, workstations, and ancillary components, factors such as power consumption, cooling requirements, equipment weight, and operating noise all contribute to the system footprint. In greenfield plant projects, companies must find the best way to reduce their control system footprint without negatively impacting project results. For companies with existing installations, reducing footprint improves the working environment for operators while reducing operational cost.
How virtualization can help
In the server room, virtualization solutions reduce the physical footprint of hardware components in the plant server room. Facility savings are both direct (consumed by the hardware) and indirect (ancillary service reductions). Running these virtualization solutions on blade hardware then provides the ultimate synergy of resource utilization provided by virtualization with the hardware density provided by blade technology.
For a typical-sized DCS cluster, using traditional methods of deployment might take 50 U (rack units) of space for the server and workstation equipment. Virtualization with blade technology could enable the same functionality in approximately 7 U of space. With the reduction in space, there is a corresponding reduction in weight, power consumption, and cooling. Not only is the system footprint reduced in size, but also the space it does consume is more predictable. This is particularly advantageous with packaged solutions where there is a desire to have a standardized layout, with the flexibility to accommodate the individual needs of customers.
When power requirements are reduced, there is also a subsequent reduction in the amount of uninterruptible power supply (UPS) capacity required by the equipment. Given that the equipment runs cooler, there is a corresponding power reduction due to minimized cooling needs. Both the UPS and cooling equipment are lighter as well.
The above footprint benefits for server rooms are particularly important for industries such as oil and gas, where offshore facilities have inherent space constraints and other physical and operational considerations.
In the control room, virtualization and thin client visualization are two powerful technologies that are complementary and even more effective when implemented together. In industrial environments, these technologies intersect when thin clients are connected to virtualized systems to provide visualization and operator interface.
A thin client is a stateless, fan-less appliance that has no hard drive, consisting only of simplified hardware and software. In contrast with a regular deployment, applications, sensitive data, memory, and so forth, are stored back in the data center when using a thin client.
Virtualized servers with a thin client operator interface are the best option for many applications commonly found in the plant control room. Like the server room example, users can optimize the same footprint vectors—equipment space, cooling, and noise. This is achieved through the thin client’s compact form and lower power usage, and lack of rotating parts such as hard drives and fans. It is not even a requirement that thin clients are co-located in the same facility or geographical region as the servers, as the link to the server is made via a network connection, and all the core software and performance reside in the host.
Paul Hodge is Experion infrastructure and HMI product manager for Honeywell Process Solutions.
- Growing sophistication of control equipment is reducing the collective amount and size of equipment, permitting more efficient use of plant space.
- Energy use has also reduced direct and ancillary costs as more efficient equipment requires less cooling, etc.