Mainframe users still stuck on IBM's previous-generation OS/390 operating system now have a compelling reason to switch to the current z/OS: IBM will stop new sales of the OS/390 December 17, 2002.
The company's zSeries manager in Australia, Janice Hui, said that after that date customers will no longer be able to order the OS/390. However, IBM will continue to support existing installations until September 2004.
"More than half of the workload on IBM mainframes in Australia is already running on zOS; customers are migrating from OS/390 to zOS for business reasons," Hui said but was unable to provide specific customer numbers.
The announcement comes roughly 18 months after IBM started shipping the 64bit z/OS along with its zSeries mainframes in March 2001.
To ease the migration from a 31bit environment to that of a 64bit, IBM is offering OS/390 customers a "bimodal migration program".
Under the program, users that move to z/OS on a zSeries machine can run the operating system in 31bit mode for six months before being required to operate it in full 64bit mode.
The program reverses an IBM policy that mandated that users run z/OS only in full 64bit mode on zSeries mainframes. Currently, the OS/390 can run on zSeries hardware in 31bit mode.
In the future IBM will also introduce new releases of its mainframe operating systems only once a year instead of twice annually, as is the current practice, according to US-based IBM director Pete McCaffrey. The change is being made because mainframe users have typically tended to upgrade their operating systems on 12- to 18-month cycles, he said.
Clipper Group analyst Mike Kahn said the move is also the result of IBM trying to improve quality and cut the costs involved in refreshing its mainframe operating systems.
"It costs IBM a lot of money to introduce new features and qualify each new release," he said.