Operating Systems

Mainframes of the Gods

2 Pages

Freeway, Raptor, T-Rex, Ptero, Danu—all these names have been important to z/Journal readers in recent years. This article discusses IBM’s evolution over the last few years, and introduces its newest mainframe, the System z9 109. If you don’t recognize the names above, you will by the end of this article!

In 2000, IBM made an audacious change. The industry had enjoyed more than 35 years of mainframe evolution, from System/360 through S/370 to S/390. (The missing link—what should have been called System/380—was instead name d Sy s t em/ 3 7 0 Ex t end e d Architecture, or S/370-XA. This anomaly may have resulted simply due to marketing choices, but may also have occurred in part because of the System/38. Released in 1978, the System/38 was descended from IBM’s Future Systems project, which would have replaced the System/370 with a revolutionary but incompatible architecture, and was almost named System/380.)

In a sweeping move, IBM in 2000 renamed all its processor lines as “eServers.” Netfinity PCs became eServer xSeries; RS/6000 RISC machines become pSeries; the AS/400 became iSeries; and the S/390 became zSeries.

The move was more than cosmetic. Historically, the different product lines were developed and sold by different parts of IBM. This led to fragmentation and confusion: The site that needed a medium-size system might be wooed by both a mainframe and an AS/400 sales representative, each claiming their product was superior, even though both were from the same company!

At times, this internal rivalry caused IBM itself difficulty making rational decisions. For example, the IBM PC Server S/390, or P/390, was a PC workstation that contained a special card that provided S/390 processing capability. Introduced in the mid-90s, the P/390 almost didn’t make it to market because the RS/6000 organization within IBM fought against it. Their premise was that the mid-size companies the P/390 would appeal to were their territory, and how dare the mainframe folks poach their customers! Of course, the reality was that companies that needed a smaller mainframe were unlikely to even consider an RS/6000. If forced to migrate to another platform, they’d suddenly find a plethora of choices available, including Sun, HP, and DEC, all of which had successful Unix architectures competing with the RS/6000.

The historical separation across hardware lines also meant that different divisions were solving the same problems with little interoperability: Peripherals such as tape drives were rarely interchangeable, and the machines shared little visual commonality. Since the reorganization, hardware cross-pollination has resulted in iSeries and pSeries machines sharing underlying Power processors; both integrated and outboard xSeries co-processors for iSeries enabling tightly coupled Intelbased computing within an iSeries chassis; and all four families sharing storage, via the TotalStorage “Shark” arrays.

The shift to all-black chassis, echoing the successful tradition of the ThinkPad laptops, also provided a visual family tie. And the rumored “eClipz” project will use multiple common components for machines from embedded systems to future mainframes. The processors and microcode will vary, but the rest of the machine—I/O subsystem, memory, hardware console, power, packaging and cooling—will be shared.

With the eServer re-branding, the IBM server sales teams were also integrated. Instead of selling four different lines, IBM now sold eServers. The move wasn’t without risk. Many thought re-branding was a real gamble and could lead to a dilution of the overall IBM brand, loss of “mindshare” and market share.

Coupled with new, sexier designs and a concurrent push for Linux on all platforms, the eServer consolidation was a success. IBM has led the server market for the last five years. They even created the first ever television advertisements for mainframes!

During this period, the zSeries name became a recognized synonym for mainframe, and four zSeries lines were released: the original z900, followed by its little brother, the z800, and then the z990 and z890.

2 Pages