AFAIK, SMS manages that DS1LSTAR is enforced when reading a dataset. That is the difference between datasets on SMS managed and non-managed volumes. That is also why an empty SMS managed dataset can occupy zero tracks.
Kees. > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > Behalf Of Jesse 1 Robinson > Sent: 27 August, 2019 22:13 > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: SMF PUZZLE > > I can't say for sure how it works now, but at one time IEBGENER did not > depend on (or pay any attention to) DS1LSTAR. It would read successive > blocks of data until EOF was encountered, or an I/O error occurred because > of differing/invalid BLKSIZE. It provided a way to salvage data from a > file that was being written to but never closed because of a system crash. > (I did say 'at one time'). OTOH ISPF Browse for example would report (and > still does) a data set as empty if DS1LSTAR so indicates regardless of > actual data on a track. > > As I documented in a previous post, even a temporary (non-SMS) data set > gets created with an actual EOF that is recognized on subsequent input. > > . > . > J.O.Skip Robinson > Southern California Edison Company > Electric Dragon Team Paddler > SHARE MVS Program Co-Manager > 323-715-0595 Mobile > 626-543-6132 Office ⇐=== NEW > robin...@sce.com > > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf > Of Vernooij, Kees (ITOP NM) - KLM > Sent: Monday, August 26, 2019 11:15 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: (External):Re: SMF PUZZLE > > AFAIK, no EOF is written, but LSTAR is set to zero which is recognized by > SMS that the dataset is empty. > EOF is data and needs a track to write on, while SMS datasets can be zero > tracks and still read empty. > > Kees. > > > > -----Original Message----- > > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] > > On Behalf Of Seymour J Metz > > Sent: 26 August, 2019 19:14 > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: Re: SMF PUZZLE > > > > If you are configured for an automatic EOF on new files, then > > Allocation writes the EOF before your application gets control; there > > is no OPEN involved. > > > > > > -- > > Shmuel (Seymour J.) Metz > > http://mason.gmu.edu/~smetz3 > > > > > > ________________________________________ > > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on > > behalf of Charles Mills <charl...@mcn.org> > > Sent: Monday, August 26, 2019 12:03 PM > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: Re: SMF PUZZLE > > > > Interesting hypothesis. Should be easy enough to verify. > > > > Charles > > > > > > -----Original Message----- > > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] > > On Behalf Of Ron Hawkins > > Sent: Sunday, August 25, 2019 11:25 PM > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: Re: SMF PUZZLE > > > > All, > > > > Could it be that the EOF mark on the file is a DADSM function outside > > of the control of the program, and that is why there is no SMF record > > from an unopened, empty data set? > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ******************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ******************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
