isham research
(This discussion has been overtaken by events. The current version will be found here)
2003 will see the biggest reduction ever in IBM's mainframe installed base - over 60 models currently in use in hundreds of installations all becoming unsupported within a six-month period.
The following list is extracted from IBM Announcement Letter 602-015, dated 18 June 2002:
| System | Model |
|---|---|
| 9021 | 520, 640, 660, 711, 740, 820, 821, 822, 831, 832, 860, 900, 941, 942, 952, 962, 972, 982, 9X2 |
| 9121 | 180, 190, 210, 260, 311, 320, 411, 440, 480, 490, 511, 521, 522, 570, 610, 621, 622, 732, 742 |
| System | Model |
|---|---|
| 9221 | 120, 130, 150, 170, 191, 200, 211, 221, 421 |
| 9672 | E01, E02, E03, E04, E05, E06, E07, E08, P01, P02, P03, R11, R21, R31, R41, R51, R61 |
For the VSE user a significant number of systems - such as the Multiprise 2000 - that are not listed above will not be supported by VSE Release 2.7. Although this is not yet an issue because VSE 2.6 continues in support, it is a point to be borne in mind for the future - on IBM's normal schedule, support would be dropped in June 2004.
When System/360 was announced, IBM was proud of its universal application and its scalability - over a performance range of 1:200 within five years of launch.
Sadly, the dumbest software pricing policy in history has killed off the low end of this range - IBM has not launched a new low-end system in its mainframe range since the 9221-2xx in 1994. Not because of any technical issues, and not because such hardware was uneconomic - but because software pricing policies made them unaffordable. Budget blocks within customers have also prevented cascading of second-hand machines, and successive software releases (especially the Language Environment and Turbo Dispatcher under VSE) have squeezed users who have nowhere to go but to Sun or HP.
Many of these systems are old; the 9221-130 and 9221-150 are still installed in significant numbers although they were first announced in 4Q1990. A handful of 9121s date from the same era. These machines have been left under maintenance simply because IBM has been ignoring the low end of System/390 - the absence of new machines has forced it to support the old ones. Architectural enhancements have been limited to the top end - meaning low end users cannot take advantage of more modern software such as z/OS even if they want to. Although the Multiprise 2000 series (itself not z/OS capable) is still in maintenance, there are very few on the market and none at all at the low end.
IBM has no offering for these customers - a dramatic shift from a historic policy of not abandoning its users.
A great many users will have a real problem - applications that cannot be replaced quickly running on hardware for which service and parts may not be available. As as predicted last year, the entry point for current hardware is now the 2066-0A1 at 80 MIPS - the 40 MIPS 2066-0E1 being non-viable because of the maintenance charges on the mandatory IFL. The 2066-0E1 and 0A1 are too powerful for most of the users being orphaned this year - the moratorium on higher software charges applies only to IBM software and is limited to 48 months; enough time, perhaps, to get off the platform. These IBM customers need a system of appropriate size - even if given as a gift, a larger system can bankrupt a small company with its software costs.
New z/OS and VM/VSE systems of less than 80 MIPS are, however available - and endorsed by IBM - via emulation of the System/390 and zSeries architectures on other platforms such as Intel. At present, the only IBM-approved product is Flex-ES from Fundamental Software and its partners such as Cornerstone Systems and T3 Technologies..
Flex-ES is now available in a 64-bit zArchitecture-compliant (ESAME - ARCHLVL=2) form. Independence of hardware Architecture Level Sets is a further advantage for emulation; the ability to switch between, e.g., ESA mode and either 31-bit or 64-bit z/Architecture via a parameter presents possibilities for regression testing across Architecture Level Sets.
Another idea would be to use a suitably partitioned Intel or AMD server such as IBM's xSeries 440 to provide a System/390 environment on one or two Intel processors, with native Intel Linux or other environments on other processors. Hitachi has open-sourced a Linux file system with potential for accessing legacy System/390 DASD data direct from Linux.
Emulation is increasingly being adopted for production in many sites - especially good results being achieved with I/O bound workloads. Performance-limiting measures to qualify FLEX-ES systems for 8 MIPS ESL licenses (even on 2.4GHz Intel processors) are well proven - these could be expanded to provide performance points tailored to each of the lower Processor Groups, thus preserving users' current charge levels.
Such a system - an open-ended Intel-based server running a System/390 workload at a specified Processor Group performance level, combined with Linux (or other) workload(s) on the other engine(s), would reduce the pressure for early migration, allowing it to proceed in a more controlled manner or be deferred. Interim growth could be catered for by lifting the system to the next Processor Group, with an appropriate adjustments in software charges. It might prove easier to justify investment in such a system than in one dedicated to the System/390 environment. If the migration stalls, the Linux portion of the system could be upgraded with no adverse effects on software charges for the legacy workload.
Emulation opens other possibilities. Not only does it lower the entry cost for ISVs wishing to develop for or port applications to Linux/390 and/or z/OS, it also allows a mainframe environment to be run on a laptop - over 150 such systems have been shipped. Demonstrating System/390 applications has always been difficult; it is hard to do it effectively over a dial-up link - either the entire system has to be installed at the prospect's site or all of the customer's decision makers have to visit a demonstration data centre. The latter can be a little like herding cats. Only rarely can applications be demonstrated satisfactorily via dial-up links. Now, a humble IBM ThinkPad can run z/OS or Linux/390 under Linux - and fit in a salesman's briefcase.
Comments on the above ideas are welcome at phil@isham-research.freeserve.co.uk - all input will be treated in the strictest confidence - no contact of any kind will result unless requested.
Older articles are in the archive