Michael O'Byrne wrote: >When I was doing DOS to MVS conversions for IBM (30+ years ago) the >recommendation would be to use IMS-DB to support DL/1 (hierarchical >database mapped to hierarchical). Today, I would recommend evaluating a >conversion to DB2 or perhaps the use of a product which maps IMS DB to >DB2.
Even if you decide to do that, you might prudently defer database restructuring and data migration to Phase 2 (or Phase 3) of your overall project, to keep your Phase 1 more concise and tractable. Or Phase 1 could be the database only, and you leave some or all of the applications in place at least during Phase 1. For example, you can license the DB2 Client Edition separately on z/VSE, and then you can configure the DB2 Client to store/retrieve data over in DB2 for z/OS. In this approach you'd likely migrate the data to z/OS and make some comparatively small code changes related to data access logic, but that would be the extent of Phase 1. In Phase 2 you'd tackle other application-related work. Another option is the z/VSE VSAM Redirector, to facilitate migration of any/all VSAM data that z/VSE manages, typically to DB2 for z/OS. This approach applies if you have z/VSE-based programs that access z/VSE-based VSAM data. In Phase 1 you can move the data over into z/OS, but the applications don't change and don't move. Then, in Phase 2, you start moving some applications to z/OS if you wish, possibly with the aid of IBM's CICS VSAM Transparency for z/OS. There are also some interesting interoperability options between CICS Transaction Server for z/VSE and CICS Transaction Server for z/OS that could be quite useful. For example, you can use the z/VSE Connector Client running on z/OS (with CICS Transaction Server for z/OS, most probably) so that z/OS has real-time access to DL/I data over in z/VSE. In this approach you could start moving some applications in Phase 1, gradually, but leave the data (and any z/VSE-hosted applications that still need the data) in place until Phase 2. If you plan and execute well (very possible), at some point in Phase 2 your z/OS applications would start to store/retrieve relocated data in z/OS instead of accessing z/VSE's DL/I data. Anyway, there are a lot of interoperability options. If you decide you want to move some applications and or data from z/VSE to z/OS, interoperability is extremely helpful to smooth the path, to remove migration dependencies (applications with data, data with applications), to reduce the migration risks, and to provide the quickest delivery of whatever specific business benefits you plan. (And if there are no real, achievable business benefits, why bother? "Eyes on the prize.") I'm mentioning these interoperability examples because they may be unfamiliar to many of you, and at least some of them are newer and not mentioned in the older redbooks. -------------------------------------------------------------------------------------------------------- Timothy Sipples IT Architect Executive, Industry Solutions, IBM z Systems, AP/GCG/MEA E-Mail: [email protected] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
