Engineering and IT Insight: Virtualize manufacturing IT
Virtual systems are rapidly invading existing server environments. Massive racks of servers in air conditioned and environmentally protected computer rooms are being replaced by smaller racks of servers with much smaller power and cooling requirements, yet more performance, memory, and disk space. Even manufacturing IT systems, which are often housed in small server rooms closer to the shop floor, are being replaced with remote virtual servers, often on the same site but at a central location. These changes will significantly simplify many problems seen today in manufacturing systems, such as upgrade methods, backup methods, and standby methods. While the economics of virtualization will drive IT departments to virtual systems, the advantages to manufacturing mean that manufacturing IT departments should actively encourage and support virtualization.
Economics are driving companies to move to virtualization. One redundant host server with 32 GB or 64 GB of memory, a few Gigabit network connections, and supported by a multiple-terabyte RAID SAN (storage area network) disk server can cost 70% to 80% less than an equivalent capability small server farm. Load monitoring of manufacturing IT systems shows that one host server can handle anywhere from 4 to 12 virtual machines (VMs) running typical manufacturing IT applications.
Measured savings on a typical system, as presented at the December 2010 ISA/ISPE conference in Research Triangle Park, NC, documented capital equipment savings of 72% ($50,400 reduced to $13,000), yearly direct energy savings of 42% (4,788 W to 700 W), and cooling reductions of 85% (16,000 btu to 2334 btu). In one implementation a single server with 35 GB memory and 2 TB (terabytes) of disk space replaced 4 historian servers, 1 I/O server, 6 dedicated workstations, 1 backup server, 1 print server, 1 domain controller, 1 Microsoft SharePoint server, and 1 SMTP server, and still provided for a 50% growth capability. Because of these significant savings, all servers in most facilities will quickly move to a virtual environment.
The move to virtualization also brings other benefits, especially in the area of updates. One common problem in industrial systems is managing all of the updates from vendors. A typical site may have 20 to 80 applications, usually from multiple vendors, and many at different operating system versions. Managing changes to the applications and the operating systems is a full-time job, and it is especially difficult because changes to production systems must be planned far in advance so that the upgrade does not stop production. Virtualization provides a good solution to this problem.
Most virtualization systems provide the capability to make a “snapshot” of a system. This is a copy of the current system that can be used to roll back if changes made to the system must be undone, or to make copies of the current VM and clone it onto another VM. Cloning a system can be part of the upgrades process. It gives you a method to make changes to a copy of the current environment, run tests to make sure the changes work and don’t “break” anything, and then copy the changed version back to the running version. This allows you to make the changes off-line, without affecting production, but ensuring that you are working on the exact current configuration.
To make this method work, you will need to set up a complete separate environment for the cloned copies. This environment must include all of the peripheral services: I/O services (such as OPC servers), print services, domain services, security services, license services, and file share services. While you may be upgrading only one VM, you will probably need copies of all the VMs within the system to recreate the production environment. The cloned copy must be installed and tested on a completely separate network, because you do not want to have to change the name of the servers for your tests, and this requires a separate domain controller. In some environments you can run the cloned copies on the same VM host and configure the clone VMs to run within their own internal self-contained network. The cloned VMs will have no access outside the self-contained network, and no one can see into that network. Once you have performed the update and verified the update with your local tests, you can take a snapshot of the updated system and copy that to the production environment. You will still have to halt production to stop the production servers, install the copies, and restart the servers, but this will be significantly faster than installing the updates on the production system and running your tests.
Hardware and energy economics will drive IT departments to virtualization, but the additional functionality provided by snapshots and rapid cloning of systems are valuable features for manufacturing. This additional functionality will reduce production downtime and reduce the risk from upgrades that break the current system. Manufacturing IT departments should learn the VM technologies and capabilities and actively encourage and support your company’s move to virtualization.
– Dennis Brandl is president of BR+L Consulting in Cary, NC, www.brlconsulting.com. His firm focuses on manufacturing IT. Contact him at firstname.lastname@example.org. Edited by Mark T. Hoske, Control Engineering, www.controleng.com.