Emerson’s Ben Skal presented on reducing the Ovation distributed control system hardware footprint at the 2017 Ovation Users Group conference. Virtualization technology is at the heart of this hardware footprint reduction and having less workstation and server hardware to maintain. Ben’s presentation focused on:
- What is virtualization & how it works
- Appropriate uses of virtual machines (VMs)
- Benefits of VM environments in increased redundancy & reliability, reduced footprint and recovery from equipment failures
- Requirements to move from traditional workstations & server to VM
Ben opened describing virtualization which separates the operating system from the physical hardware. Multiple virtual machines can run on physical services. Server host clusters have a management console that oversees the cluster of servers on which the VMs run.
Traditionally separate PCs run database servers, historians, engineering stations, operator stations, etc. In a virtual environment, these physical workstations run as VMs in a server cluster with thin clients running remote desktops into the VMs. This configuration is recommended for non-critical applications since the loss of a server cluster would cause a loss of all the VMs running in it.
To avoid this situation, high availability virtualization architecture increases reliability has the data stored in storage area network (SAN) storage devices. If a virtual host is lost, the other virtual hosts automatically reboot on the other virtual hosts.
All networks and interfaces are fully redundant including the Ovation highway, management network, remote desktop network and each Ovation VM is configured with two virtual network interfaces. The hardware is based on Dell server technology with RAID 6 hard drive redundancy. The virtual environments for the VMs and thin clients are based on VMware. Since the thin clients do not contain local storage, they do not require patch management.
With high availability virtualization lifecycle maintenance is simplified with hardware decoupled from software, faster recovery from workstation failures and extended system life by avoiding hardware obsolescence. Deployment and maintenance are more flexible since applications such as database server can be accessed from multiple locations on the network. Cybersecurity protection is also simplified since the VMs are located together and can be patched and updated together.