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The Truth Will Set You Free

By Destination Z posted Mon December 23, 2019 03:33 PM


Anyone who's worked with mainframes has heard cringe-worthy comments about them: misconceptions, misinformation, misunderstandings, exaggerations, myths and blatant lies. Sadly, bogosity comes from many sources: colleagues, managers, airline magazines, vendors, itinerant consultants.

While it's sometimes tempting to ignore such nonsense, doing so doesn't serve your career, employer or the mainframe community. Just as websites like or quickly debunk intriguing Internet news—like the entertaining meme that entering your bank ATM PIN in reverse summons police in emergency—mainframers should counter untruths about their favorite platform.

I'd enjoy a contest seeking the most absurd mainframe myth encountered. My entry would be from when my installation was upgrading from 370/148 to 4341. A visiting industry expert mentioned casually to several management levels that we were taking a big risk because the new processor might not be fully compatible. No technical arguments or IBM assurances could calm things down. So we bought time by developing what we told management was a comprehensive architecture validation test, installed the new system, and—of course—all was well.

The Mainframe Lives!
The oldest—astonishingly long-lived—myths claim "the mainframe is dead/dying/doomed." It's tempting to answer this by pointing to Stewart Alsop’s 1991 assertion that the last mainframe would be uninstalled within five years, which led to his eating his words. And noting that while other technologies have come and gone, the mainframe simply improves. Since Alsop’s bad bet, we've seen more than a few major processor and OS generations, and we're coming up on the 50th birthday of what's still a compatible computing architecture.

“The mainframe is obsolete.” Tell that to large and small businesses worldwide—banks, insurance companies, airlines, manufacturing companies—running mission-critical solutions (not just applications or systems) on mainframes. Or ask the hundred or so new mainframe customers IBM expects to add this year. IBM has said that the number of z/OS and z/VSE CICS transactions processed daily rivals the number of Web pages served.

“The mainframe is 1960s technology.” That's true only in the sense that a 2013 automobile is Henry Ford’s Model T. IBMer Jim Elliott's wonderful mainframe history outlines its evolution since introduction in 1964 (and gives a bit of pre-history, too).

“The mainframe is a black box.” For decades, diverse system and application monitors, recorders, data analyzers and predictors have provided detailed billing, resource management and capacity planning tools.

“Mainframes are inflexible and don’t scale.” Moving from the $75,000 entry-level zEnterprise 114 to the top-end, 52,000-MIPS zEnterprise 196 (z196) provides ample room to grow. If that's not adequate, up to eight z196 systems can be connected in a single centrally managed ensemble. In fact, multiple options allow increasing in-place processor capacity with no outage, either to handle transient workload spikes or as permanent upgrades. That's flexibility.

“Mainframes cost more than distributed systems.” The complementary metal-oxide semiconductor (CMOS) processor’s evolution dramatically reduced mainframe cost structure, and processors have subcapacity increments to closely—and competitively—match requirements.

“Mainframes don’t speak modern programming languages.” That’s contradicted by the more than 1,300 sites running Linux on System z with more than 3,000 applications available implemented in, and providing current programming and development tools. There's support for J2EE, Java and other industry standards—along with traditional and still-critical languages such as COBOL.

“The mainframe can’t be important because it never comes up at meetings.” Sometimes mainframers make success look so easy that it’s taken for granted.

“Mainframe means z/OS.” Since the early days of System/360—and still—multiple mainframe OSs have satisfied varying customer needs. Today, zEnterprise is supported by z/OS, z/VSE, z/VM, Linux on System z (often run under z/VM) and z/TPF, each of which has dedicated IBM development and support, committed customer installations and a vibrant user community.

“z/VM wastes/steals valuable CPU cycles.” Those cycles are a modest tradeoff for sophisticated centralized management and resource sharing of multiple development/test/production guest systems or hundreds/thousands of virtual servers. And decades of optimization improvements make VM an industry-leading virtualization technology.

Mainframe Staffing and Skills
"Mainframes require bloated staff support." System programming productivity has improved over the years via learning and improved tools. Fewer people now tend processor and DASD resources on a scale previously unimaginable. Don't include application developers, network administrators and middleware managers in mainframe platform support—they'd be needed for any alternative systems. Mainframe capacity can often increase dramatically with no accompanying staff growth—unlike distributed systems.

“It's too hard to administer mainframes and mainframe hardware/software changes are disruptive.” That's often said by someone thinking of old-days system generation or maintenance application, or who's believed competitors' marketing fluff. System installation and updating is highly automated and error checked, with command-line interfaces replaced by modern graphical environments. Besides unparalleled reliability, current mainframes allow non-disruptive upgrades and repairs.

“Mainframe staff is hard to recruit/retain/train.” IBM’s Academic Initiative System z program seeks to ensure that the next generation of mainframe experts will be available to help more organizations leverage the superior security, availability, scalability and efficiency of the mainframe. Classes and certifications offered online and at hundreds of colleges/universities—combined with the SHARE user organization's zNextGen project—provide the next generation of skilled and motivated mainframers.

“There's nothing to learn from mainframers.” Consider various technologies innovated on mainframes, e.g., virtual machines, and only later "invented" on other platforms, and the many problems mainframers solved long ago still requiring remedies elsewhere.

"There's a generation gap between mainframers and other IT staffers." While often true—an older generation sometimes thinks progress ended with the last system they learned, while youngsters may believe the industry was born with the first system they learned—mutual respect and curiosity can conquer this gap.

"Mainframe careers are dead end or have no future." Multiple LinkedIn groups feature mainframe jobs, IBM Academic Initiative graduates find key jobs with clear advancement paths, and SHARE participants represent every career stage.

“It's hard to make mainframes secure.” Has anyone heard of mainframe malware, or of a mainframe monthly "Patch Tuesday" closing dozens of newly discovered critical exposures? Mainframe architecture and associated OS design and configuration make it the most resilient system platform, enabling holistic security rather than a piece-parts approach.

"Mainframes are isolated, not networked." That's been false for decades; all mainframe OSs and associated middleware interoperate with other platforms and the Internet, fully implementing distributed processing and industry standards including TCP/IP, Simple Object Access Protocol (SOAP) and XML.

"Mainframes don't matter in the Internet/cloud world." In fact, they provide backend transaction processing to many high-end websites, and are ideal for service-oriented architecture (SOA) applications. In addition, specialty processors (System z Integrated Information Processor and System z Application Assist Processor) offload Internet-critical workload from main processing without increasing software-licensing costs. Finally, Integrated Facility for Linux engines, optimized for the Internet's most popular OS, enable large-scale server consolidation.

"Mainframes aren't ‘green.’" Inherent capacity scalability, consolidation capabilities and improved technologies reduce system footprint, power and cooling requirements.

"Running mainframes means being in IBM's clutches." While you'll buy processors from IBM, the mainframe ecosystem includes abundant hardware/software vendors complementing and competing with IBM products. All-Blue shops are now the exception, not the rule.

So, if you hear something (stupid), say something (accurate)!

Gabe Goldberg has developed, worked with and written about technology for decades. He can be contacted at