Mainframe, Performance, Topics Podcast

Episode 13 "We'll Always Have Paris"

Listen Later

Here are the show notes for Episode 13 "We'll Always Have Paris". The show is called this because both Marna and Martin reminisce about lovely times in the City of Light.  Marna just got back from Paris with her son (the one that built his own gaming computer). They discuss what they like to do there.

Mainframe

Our "Mainframe" topic discusses what has been a popular item since more people have finished migrating to z/OS V2.2: GDGEs. Generation Data Group Extended (GDGEs) were introduced in z/OS V2.2, and should only be used after fully migrated to that release everywhere. "Old" GDGs allow >255 generations. GDGEs allow up to 999, but with a very different internal structure. GDGEs are externally usable transparently.

There is no straightforward conversion way in DFSMS. Steve Branch (alias name of "Mr. Catalog") and Marna had a six step JCL job to convert (which used IDCAMS ALTERs), and would work if the generations were SMS-managed, which was the initial use case. Several options were discussed.

  • You can do the conversions for your GDGs to GDGEs, but you need to decide if it's worth it.
  • The TSO/e RENAME will work in all the cases that IDCAMS ALTER would, plus more.
  • The shared REXX exec can be used if you want to convert NON_SMS/TAPE GDGs to GDGEs.
  • Still, if you have a gazillion references in places like JCL, it is a compelling case to take some extra one-time work and do the conversion.Mind the recalls! You'll need a lot of recall space on DASD, if you are recalling lots of data sets and they are large.
    • Performance

    Martin talked about a presentation he's been keeping updated, Even More Fun With DDF. The original presentation covered: 

    • why you should care about DDF,
    • LPAR to Service Class Level views,
    • side themes of zIIP and DB2 address spaces, and a discussion of SMF 101 and DDF.
    • Contains three different customer cases: some basic statistics, a CPU Spike case, and "sloshing".
    • SMF 30 Enclave Statistics graphing
    • Thoughts on handling clients with huge numbers of short commits
    • Matching client and server DB2 101s where DB2 to DB2 DDF
    • Production vs Feral DDF
    • Diagrams of machines connecting to DB2 via DDF

      • The updated presentation has an analysis is done using RMF and SMF 30, and SMF 101 DB2 Accounting Trace, using special code written by Martin.

      Topics
      • Sites: Martin loves to go to the museums. Especially the Louvre and Beaubourg. Marna's son doesn't like museums, so they visit other spots like the Catacombs (with a four hour wait!) and the gargoyles at Notre Dame./li>
      • Food: Marna and her son focus on cheese, and have become quite adept at all three raclette contraptions available, all ways to scrap cheese onto your plate.
      • Getting around: Martin loves the metro, which is so easy and convenient. He loves the part on the metro when you come out from underground to the raised tracks in some places. Marna did a lot of walking. (Fitbit while at Versailles registered 31k steps = 13. miles = 22 km.)
      • Pro Tips: Use the "skip the line" and make reservations very early. Buy tickets early.
        • Contacting Us

        You can reach Marna on Twitter as mwalle and by email.

        You can reach Martin on Twitter as martinpacker and by email and blogs at blog.

        ...more
        View all episodesView all episodes
        Download on the App Store
        Mainframe, Performance, Topics PodcastBy Marna Walle