Virtualization: Playing well with others

One thing that we all learn in kindergarten is to play well with others. Unfortunately that is often a lesson that vendors of many manufacturing IT applications failed to learn. Manufacturing applications are usually certified to run only on servers with no other applications. If other applications are running, then the vendor may not provide support.

By Dennis Brandl, BR&L Consulting June 1, 2006

One thing that we all learn in kindergarten is to play well with others. Unfortunately that is often a lesson that vendors of many manufacturing IT applications failed to learn. Manufacturing applications are usually certified to run only on servers with no other applications. If other applications are running, then the vendor may not provide support.

One large, well-known control system vendor requires five separate servers for its manufacturing application suite—and many of its customers, of course, also use other applications that have their own server needs. The variety of possible applications include HMI servers, manufacturing execution systems, laboratory information management systems, data historians, document management systems, communication concentrators, maintenance management systems, print servers, file servers, PLC source code control systems, and general purpose databases.

The proliferation of dedicated servers is causing a problem in many manufacturing facilities because there is not enough controlled environment space for all the servers. Often, the manufacturing servers have been placed in the few environmentally controlled cabinets somewhere near the production lines. Many times the manufacturing servers have to share space in the cabinets with telecom equipment and general I/O connections. As IT solutions are added to the factory floor, there may not be space for the required servers.

One answer to this problem is through an IT industry solution: virtualization. Virtualization has been around since the early days of computing, but only recently are major operating system vendors supporting it.

Virtualization is a method for running several independent copies of an operating system and application on the same machine at the same time. For example, a single physical server could run Linux and an Oracle database on one virtual server, and still run Microsoft Windows 2000 and an HMI application on a second virtual server, while running Microsoft Windows XP and an MS-SQL database on a third virtual server. This takes minimal overhead, because new virtualization solutions take advantage of virtualization hooks in the latest Intel and AMD chips. Most virtualization systems provide near-native performance.

Fortunately, many manufacturing applications were designed for slower servers with less memory and smaller disks than are available today. If fact, the recommended resources for most applications mean that servers often run at 20% or less utilization. Virtualization allows you to tap into the unused CPU cycles and memory, allowing more applications per server, each in its own environment. When a single large server takes the place of multiple smaller servers, you can simplify server management, improve disaster recovery, and lower administrative and hardware costs.

Virtualization is available from multiple vendors. The open source option includes XEN ( www.xensource.com ); Microsoft has Virtual Server 2005; Sun has VMWare ( www.vmware.com ) from EMC. Red Hat and Novell also provide options.

Know your boundaries

When virtualizing manufacturing systems, it is important to remember the network boundaries and collect applications at similar levels. For example, database servers, print servers, file servers, and some application servers would run in the network DMZ—the space between a firewall to the corporate network and a firewall to the control network. These applications could be virtualized to a one machine. Likewise, servers at the control network level could be virtualized without compromising the security or integrity of the network segmentation. Virtualization works best on manufacturing applications that use standard device drivers.

Virtualization, scaleable as needed, is becoming a valuable tool to allow manufacturing systems to play well with others, and simultaneously reduce server space problems.

Author Information
Dennis Brandl, dbrandl@brlconsulting.com , is the president of BR&L Consulting, Cary, N.C., which is focused on manufacturing IT solutions.