If your DATACLAS specifies a default DSORG (which can be overridden by JCL), an unopened, NEW allocation will have a valid EOF. For at least the last 25 years.
> -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > Behalf Of David Spiegel > Sent: Wednesday, May 11, 2022 10:36 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: Potential Resource Savings Techniques > > [EXTERNAL EMAIL] DO NOT CLICK links or attachments unless you recognize > the sender and know the content is safe. > > Hi Dave, > I looked at my Data Class definitions and saw nothing related to writing > an EOF. > Maybe you have an Exit or Storage Management product (e.g. CA Disk, > Mainview SRM). > > Regards, > David > > On 2022-05-11 13:27, Gibney, Dave wrote: > > I may be mistaken about the RLSE or perhaps it is a function of my default > DATACLAS. I know the EOF is there. > > > >> -----Original Message----- > >> From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > >> Behalf Of David Spiegel > >> Sent: Wednesday, May 11, 2022 10:23 AM > >> To: IBM-MAIN@LISTSERV.UA.EDU > >> Subject: Re: Potential Resource Savings Techniques > >> > >> Hi Dave, > >> I tested it. Your hypothesis is false (i.e. RLSE is not done.) > >> > >> Regards, > >> David > >> > >> On 2022-05-11 13:12, Gibney, Dave wrote: > >>> If SMS-managed and DSORG known, an unopened new allocation will > have > >> an EOF set and RLSE will be process. > >>>> -----Original Message----- > >>>> From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> > On > >>>> Behalf Of David Spiegel > >>>> Sent: Wednesday, May 11, 2022 9:20 AM > >>>> To: IBM-MAIN@LISTSERV.UA.EDU > >>>> Subject: Re: Potential Resource Savings Techniques > >>>> > >>>> Hi Paul, > >>>> Allocation does allocation and nothing but allocation. > >>>> It does not write anything at all. > >>>> > >>>> Regards, > >>>> David > >>>> > >>>> On 2022-05-11 12:17, Paul Gilmartin wrote: > >>>>> On Wed, 11 May 2022 15:53:20 +0000, Farley, Peter x23353 wrote: > >>>>> > >>>>>> Only if your SYSIN is not DUMMY. When SYSIN for IDCAMS is > DUMMY > >> it > >>>> does (and can do) nothing at all, rather more expensively in CPU time > >> than > >>>> IEFBR14, but still nothing by comparison. > >>>>>> Only if you are allocating and using REPRO from a DUMMY to a new > >>>> sequential file or an actual DEFINE for a VSAM cluster for instance > would > >>>> IDCAMS do what you describe. > >>>>> Will it not write an end-of-file at the first extent and RLSE all but > >>>>> the first allocation unit of SPACE? > >>>>> > >>>>> (I suspect the OP did not intend his use of "SYSIN".) > >>>>> > >>>>> In the Bad Old pre-SMS Days, I sometimes relied on a primary > >>>>> allocation of 0 to preclude subsequently reading residual data. > >>>>> > >>>>>> -----Original Message----- > >>>>>> From: <David> <Mingee> > >>>>>> Sent: Wednesday, May 11, 2022 11:46 AM > >>>>>> > >>>>>> IDCAMS does an open and close on the new file and writes zero > >> records, > >>>> so if RLSE is coded with the SPACE for output file(s) then the unused > trks > >> or > >>>> cyls > >>>>>> Are released. Secondary space will be used if needed when data is > >>>> created in the file later. > >>>>>> -----Original Message----- > >>>>>> From: David Spiegel > >>>>>> Sent: Wednesday, May 11, 2022 11:07 AM > >>>>>> > >>>>>> I do not understand this at all. > >>>>>> How does any program differ from IEFBR14 (with respect to > >>>> allocation/freeing unused disk space by DD Statement)? > >>>>>> Maybe your shop has an Exit or add-on product which does Storage > >>>> Management? > >>>>>> On 2022-05-11 01:53, <David> <Minge > wrote: > >>>>>>> 5. Consider changing IEFBR14 for allocating new files to IDCAMS > >> with > >>>>>>> SYSIN DD DUMMY. This will release unused disk space. > >>>> ---------------------------------------------------------------------- > >>>> For IBM-MAIN subscribe / signoff / archive access instructions, > >>>> send email to lists...@listserv.ua.edu with the message: INFO IBM- > MAIN > >>> ---------------------------------------------------------------------- > >>> For IBM-MAIN subscribe / signoff / archive access instructions, > >>> send email to lists...@listserv.ua.edu with the message: INFO IBM- > MAIN > >> ---------------------------------------------------------------------- > >> For IBM-MAIN subscribe / signoff / archive access instructions, > >> send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
