What are the choices for OS/390 upgrade?

Businesses must make tough upgrade choices this year or risk running unsupported operating systems on their mainframes. We look...

Businesses must make tough upgrade choices this year or risk running unsupported operating systems on their mainframes. We look at the options.

Gartner has warned businesses running the IBM OS/390 2.10 mainframe operating system not to count on IBM extending support beyond the September 2004 deadline.

Last December Computer Weekly reported that users had until March to buy IBM's z/OS 1.4 operating system, the last release that will coexist with OS/390 2.10. Unless they buy this release users risk running an unsupported operating system after September.

In a research paper Gartner analyst John Phelps said users had to plan their migration strategies now. "With support already extended one year beyond the normal three-year window and the emphasis IBM has placed on saying support will end," said Phelps, there was little likelihood of a further extension.

Even if IBM did offer additional support it would not be for more than six months and would come "at a hefty cost", he wrote.

Gartner said the main options available to users are to run OS/390 2.10 in an unsupported environment; move to z/OS; or move to another platform.

Unsupported OS/390 2.10

Phelps urged users to avoid running OS/390 2.10 unsupported. He said, "When the product goes unsupported, the enterprise still pays the full licence charge but will not receive any more maintenance."

Firms considering this option should assess how critical the system is; the impact an outage would have on the business; and the stability of the system, said Phelps. Users also need to consider how long they would need to run OS/390 2.10 unsupported.

Migrate to Unix/Windows

Users could consider moving off the mainframe completely. But Phelps warned that migrating to Unix or Windows could be disruptive to business. According to Phelps, this would require the migration of core applications and staff skills.

He said, "Enterprises must weigh the cost to migrate, the lost time to work on new projects, the possible loss of functionality such as high availability and security, and the change in skill sets."

Businesses that began making preparations during 2003 could meet the September 2004 deadline. Other users may benefit from rival suppliers providing them with teams to assist in the migration, Phelps said.

Upgrade to z/OS 1.4

For most users, migrating to z/OS 1.4 would be the most straightforward option, said Phelps.

However, he warned this meant users would need to run the appropriate level of hardware, Architecture Level Set 2. Users operating G4 mainframes and below would have to upgrade hardware as well as software to move to z/OS 1.4.

Suitable hardware includes the Multiprise 3000, G5, G6, z800, z900 or z990 systems.

Use an emulator

Smaller users who require up to 60mips may consider an Intel-based mainframe emulation, which enables the mainframe software to run on an Intel-compatible PC server.

One example is Fundamental Software's Flex-ES. An OS/390 2.10 user from an agricultural equipment manufacturer told Computer Weekly that he was planning to purchase Flex-ES as he reduces the company's use of its existing IBM Multiprise mainframe. "Flex-ES offers significant cost savings," he said.

Along with allowing the company to migrate to z/OS 1.4, he said the 18mips Flex-ES server would incur considerably lower licensing costs than the 48mips Multiprise it replaces.

IBM user group Guideshare Europe is running an event on moving from OS/390 to z/OS 1.4 on 20 January at Nationwide building society's Swindon head office.

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