Z/OS: Users Expect Big Savings

Upgrades of mainframe operating systems don't usually generate much excitement. But users say IBM's z/OS - the new version of OS/390, introduced in October of last year - is different.

Not only does it marry the old mainframe disciplines with the distributed server world, but it also promises big changes in software pricing.

The new z/OS metering technology - and the resulting new pricing model - could sharply reduce the cost of applications for mainframes. Naturally, that has IT managers ecstatic. "Stupendous savings," predicts Dan Kaberon, parallel sysplex manager at Hewitt Associates LLC in Lincolnshire, Ill. "The software savings will substantially exceed the cost of the new mainframe hardware that we have installed this year."

Hewitt, a large mainframe user, is one of the country's biggest human resources outsourcers. The company has installed six of IBM's new z/900 mainframes so far this year.

The excitement is understandable because IT managers have complained for years about the current mainframe software pricing models. And software costs have been a crucial factor in driving applications off mainframes in the past several years.

Z/OS enables what IBM calls a Variable Workload License Charge, which will allow mainframe users to pay for software based on the size of their workloads, not on the overall capacity of their systems.

This support for subcapacity licensing is crucial. Mainframe users have criticized the unfairness of capacity-based license models that tie software prices to the size of a system - the bigger the system the more the software costs.

"It's like buying a Cadillac seat cover and being asked to pay the price of a full Cadillac," says Harry Roberts, CIO at Boscov's Department Stores Inc. in Reading, Pa.

With z/OS, IBM has laid the groundwork for an alternate pricing structure under which the cost of software will be lower than or equal to current pricing models for the same capacity, says Pete McCaffrey, program director of IBM's enterprise server group.

Key to this is an upcoming z/OS feature called the IBM License Manager (ILM), which essentially gives IBM and other software vendors a license compliance tool to monitor customers' average software usage and then charge them based on that, he says.

Once installed on a mainframe, the ILM monitors the average use of a piece of software over four-hour periods and relays that information back to IBM or third-party software vendors. If a customer's average use during a given four-hour period exceeds the current licensed capacity, that customer will be required to pay additional fees.

The result: Users will be able to license software based on expected average workloads rather than on peak workloads, McCaffrey says.

To qualify, customers must first move to IBM's zSeries 900 mainframe hardware and run the z/OS operating system in full 64-bit production mode. And major third-party mainframe software vendors also have to agree to license their software in this manner for subcapacity pricing to really make a difference. Traditionally, major software vendors have dragged their heels when it has come to supporting new pricing models, so their support will be crucial.

Alas, ILM was supposed to have become available by September, but its availability has been pushed back to the first quarter of next year.

In the meantime, IBM has made available an interim, downloadable Workload Capacity tool that will allow users to take advantage of subcapacity pricing. But it doesn't have the same license compliance-monitoring feature that ILM will deliver.

Blending Old and New

But z/OS is about more than just new software pricing. A lot about the operating system - such as its wide range of system services, and its integrated database and transaction monitors - plays to traditional mainframe strengths, says David Floyer, an analyst at IT Centrix Inc., a mainframe consultancy in Mountain View, Calif.

At the same time, its 64-bit architecture, sophisticated new resource-sharing and dynamic workload management capabilities, enhancements in IP networking, and growing Linux and Unix support make the mainframe more acceptable in distributed server environments as well, Floyer says.

"With the z/OS, IBM is trying to make sure users can get as much as possible from [open] environments without losing the core competencies of mainframe technology," Floyer says.

For instance, the ability to dynamically add memory and capacity to applications that need them makes for far more efficient use of hardware and network resources, says Jerry Skaggs, vice president of IT operations at United Parcel Service Inc. in Mahwah, N.J.

The company has 15 zSeries mainframes with a total installed capacity of more than 19,000 MIPS, accessing more than 175TB of mainframe and Unix storage data. The systems - each of which comes with up to 2,500 MIPS capacity and a much smaller footprint than IBM's previous mainframes - also make for great server consolidation platforms, according to Skaggs.

UPS is also investigating whether it would be more cost-effective to run some of its current Wintel and Unix applications in a Linux environment on mainframes, says Skaggs.

Boscov's has installed IBM's new z/900 technology not only to boost capacity for its traditional big-iron workload but also to consolidate applications from several Wintel servers, Roberts says.

During the next several months, Boscov's will migrate several core Wintel server applications, starting with its file servers and database servers, to a Linux environment running on a z/900 mainframe. The move should greatly reduce the "care and feeding costs" associated with running those same applications in an Intel-based server farm environment, says Roberts.

"Care and feeding" in a Wintel world requires about one technician for every 10 servers. Running the same applications on virtual Linux partitions on a mainframe could make it possible for one or two people to look after 45 servers, Roberts estimates. "The z/900 is much more than a mainframe. . . . It is an enterprise server that provides you with a very flexible [application] environment to run mainframe and server applications" side by side, he says.

The 64-bit support in z/OS is also important for most users, though more applications and middleware need to get 64-bit-enabled before they can take full advantage, says Steve Gilde, a director at ACI Worldwide Inc., an Omaha-based developer of software for automated teller machine (ATM) and consumer banking applications.

The 64-bit support allows more of an application's data to reside in system memory, where it can be accessed much faster than if it had to be accessed from disk. "If someone is in an ATM or checkout line, every millisecond counts. If we can push some of our critical data into memory, we can make that process faster," Gilde says.

Similarly, some of Hewitt's applications require several instances of the DB2 database - plus other subsystems such as CICS and Web server applications - to run on a single server. But because of memory addressability limits on previous operating systems, Hewitt had to split the subsystems over multiple systems. With a 64-bit environment, it's possible to run everything on one server, Kaberon says.

The z/OS mainframe heritage and its growing support for newer environments "makes all the sense in the world for us," says Roberts at Boscov's.

The company's existing investment in mainframes makes it crucial to continue upgrading that environment. Z/OS enables that to happen, he says, while also offering "a great answer to growing server farms."

Copyright © 2001 IDG Communications, Inc.

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