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IBM ends 31-bit z/OS mainframe support

On April 1, IBM stopped service for z/OS v1.4 and v1.5, ending its support for 31-bit z/OS on the mainframe. For some users, that means a mandatory -- and expensive -- hardware upgrade.

IBM stopped supporting 31-bit z/OS on the mainframe on the first of this month. For Ron Avery, the operating systems manager in Polk County, Iowa, it was like a cruel April Fools' joke.

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Avery had an IBM mainframe 7060, which dates back to 1999 and is one of the S/390 Multiprise 3000 models that is still popular among smaller mainframe customers today. It was running z/OS v1.4, which along with v1.5 is one of the 31-bit OSes IBM no longer supports. With v1.6 and above, z/OS requires a 64-bit zSeries or System z mainframe starting with the z800.

"We're a fairly small mainframe environment," Avery said. "We had no impetus for 64 bit."

But they did have an impetus. They had to upgrade because its mainframe runs the county's mission-critical tax accounting application.

"We were driven to it basically by IBM dropping its support of z/OS 1.4. We do not want to be on an operating system that is not supported by IBM. We are running the largest financial engine in the county."

It's a situation many mainframe shops have faced in recent months. Jim Rhyne, chief architect for enterprise software at IBM, said some companies are able to strike deals to extend IBM support for 31-bit z/OS. But for the most part, Rhyne said that IBM has given customers plenty of time to migrate off z/OS 1.4 and 1.5, as the end-of-service announcement was made in August of 2003.

The announcement doesn't affect 24-bit or 31-bit applications (such as CICS or IMS) running in z/OS 1.6 or later in 64-bit mode, which IBM will still support. What's new is that IBM is forcing customers who have older mainframes to buy new hardware if they want to run an IBM-supported version of z/OS.

Rhyne said some customers will just go off support, but that is rare and usually only happens if the user is transitioning off the mainframe to another server platform.

Avery had no desire to move off the existing mainframe and knew that extended support from IBM on z/OS 1.4 would only last so long. He felt the only option was an upgrade.

For Avery, upgrading the mainframe's operating system meant a hardware upgrade that will end up costing the county three-quarters of a million dollars over the next three years. To get that price, Avery had to look to alternatives rather than just going with the default -- buying an IBM mainframe.

IBM mainframe alternative

Before moving to Polk County, Iowa, Avery was in Silicon Valley for 15 years and worked with plug-compatible mainframes from Amdahl Corp. Amdahl is no longer in business, but Avery found that Platform Solutions Inc. and T3 Technologies Inc. offered suitable replacements.

Platform Solutions produces plug-compatible mainframes that run on Intel Itanium 2 processors and work with z/OS. T3 Technologies has a licensing and distribution agreement with Platform Solutions to also sell plug-compatible mainframes. Avery found that going with a Liberty Server from T3 Technologies would cost about $3,000 less per month than buying an IBM model. Over the course of the three-year lease he has with Platform Solutions, that adds up to savings of more than $100,000.

Meanwhile, Platform Solutions and T3 Technologies are offering 31-bit support to customers who, unlike Avery, don't have to move to 64 bit to keep the IBM support.

"We did a survey of 600 mainframe shops," said Christian Reilly, Platform Solutions' vice president of product management. "We found that about 10% of the community did not make the jump to 64 bit."

For Avery, though, the problem wasn't the software itself. It was the support that his organization needed to go with it. If he could have run an IBM-supported z/OS on the 7060, he probably wouldn't have bought the new plug-compatible mainframe.

"It was running absolutely fine," Avery said about z/OS 1.4 on the 7060. "We had no problems since we installed it. We've never had a problem with the IBM system software. It's the best in the business from our perspective. But we want to stay on a supported operating system, so we were essentially left with no choice."

As for the 7060? It's sitting in the corner with the power off. Avery said the county may keep it as a backup machine but hasn't decided yet.

Let us know what you think about the story; e-mail: Mark Fontecchio, News Writer.

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