If you’re a newcomer to the IT industry, you might think virtualization is a relatively new development, but it’s not. At MetLife, virtualization has been around since the ’70s, when the company started using the MVS and VM operating systems on the mainframe. Since then, MetLife has continued to look for ways to leverage the newest technology with the latest developments in virtualization, specifically on the mainframe, to improve performance and capabilities. As part of this commitment, MetLife in recent years sought to prove Linux could run on the mainframe—and do so without special skills and personnel to install or operate—while simultaneously enhancing reliability and decreasing cost.
However, before we examine that exciting journey, a review of how MetLife first incorporated virtualization into its environment is necessary to provide insight into how we’re using mainframe virtualization today.
MetLife and Mainframe Virtualization
During the ’70s, MVS was used for MetLife’s critical production systems with CICS as its online transaction system and VM was used for application development. The VM environment grew to support more than 30,000 users and included one of the first types of email systems called PROFS. VM users appeared to have their own set of resources (storage, processor, printer, etc.) even though all these resources were shared.
On MVS, MetLife became an early participant in the use of DB2 and Systems Managed Storage (SMS); the latter facility allowed storage capacity to be efficiently shared among many users and workloads. MVS evolved into z/OS and continues to support MetLife’s critical production applications with the addition of IMS as another transaction system. Eventually, application developers migrated from VM to Time Sharing Option (TSO), and PROFS gave way to the adoption of Lotus Notes. VM was then used only to support a small number of disaster backup and recovery MVS guest machines.
Virtualization in Recent Years
Maximizing efficiencies. The inherent virtualization capability of the mainframe operating system, combined with the continually improving price and performance of hardware, has enabled MetLife to efficiently support its business applications on the mainframe. Hundreds of applications and thousands of individual users are supported on z/OS on just four CPU footprints. They’re able to seamlessly and securely share data with each other. The supporting storage (DASD, tape, and directors) is comprised of only a dozen more physical boxes using a fraction of a computer bay. So, in terms of raised floor space and power consumption, the MetLife mainframe environment is already “green,” but there are further opportunities to take advantage of its efficiencies.
Virtualizing the tape environment. Another area in which MetLife has taken advantage of virtualization on the mainframe is in its tape environment. Leading up to the ’90s, IT managed a combination of large manual and automated tape operations (tape silos) that presented myriad issues, including persistent media problems and excessive tape handling requirements, and required large amounts of raised floor space. These issues were resolved with the use of a Virtual Tape Subsystem (VTS). VTS appears to the system as individual tape drives, but is actually a storage or DASD buffer with back-end tape drives. No application changes were required to migrate to this technology. Also, any critical files or archive files that are legally required to be offsite are copied to the local VTS in MetLife’s primary data center and then mirrored to a remote VTS in MetLife’s secondary data center. This eliminates the need to send any tapes to an external location—protecting the company from inadvertent data loss.
Integrating company acquisitions more efficiently onto MetLife’s mainframe. MetLife has used its technology to seamlessly integrate multiple acquisitions over the past 10 years into a shared/virtualized mainframe environment. The most recent major business integration was completed in less than a year partly due to these features of the mainframe environment.
Virtualization Business Drivers