On Wednesday, 03/01/2006 at 11:17 EST, "A. Harry Williams" <[EMAIL PROTECTED]> wrote: > I disagree. LIST is by definition a R/O type function, and > doing any sort of write is BAD. Even IDCAMS doesn't do that. > And to do so silently under the covers if a certain hardware > switch is flipped is mindboggling. It is also violates the > principal of least surprises. DSF never does anything without > asking, or being told to not ask.
Yes, we and DSF ultimately came to the same conclusion this evening. The offending PTF will be marked PE and a new APAR will be created to add a new "CPVOL REFVTOC" (or something like it) to cause the VTOC to be rewritten to match the size of the disk and remove all mention of alternate cylinders. And I have the answer to why the alternate cylinder count is so dang important: DFSMSdss on MVS will include them in the total cylinder count, resulting in a mismatch between the number of cylinders in the VTOC (primary + alternate) and the number of cylinders returned by the device. That mismatch gives DSS users a warning every time about the mismatch. A cry went out across the land.... But rather than fix DSS's boneheaded view of the universe and simply ignore the now-irrelevant alternate cylinder count, it was decided that the correct solution was to fix-up the VTOC instead. That resulted in REFORMAT REFVTOC on DSF/MVS. So now VM will have the same function (e.g. CPVOL REFVTOC) and fixing the problem will be left up to the sysprog. Now if you get into trouble with this it won't be *our* fault!! :-) Thanks to Jeff for bringing it to our attention. The DSF folks learned some things along the way and I got to stroll down Alternate Cylinder Memory Lane. A special thanks to Steve Wilkins, my colleague, for knowing exactly who to call in DSF Land and for helping with some experimentation. I hope I to see many of you soon in Seattle for SHARE. Alan Altmark z/VM Development IBM Endicott
