What is "unblocked"? There is a difference between RECFM=F,LRECL=200,BLKSIZE=200 and RECFM=FB,LRECL=200,BLKSIZE=200?
You may want to submit an RCF against the COBOL documentation asking for clarification. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List [[email protected]] on behalf of Pommier, Rex [[email protected]] Sent: Tuesday, June 14, 2022 6:06 PM To: [email protected] Subject: SMS confusion on when system determined blocksize is used Hi list, I had a strange one thrown to me from a developer and I'm hoping somebody can point me to something to explain why this is happening. Environment is z/OS 2.4 and Cobol 6.3,pretty vanilla. I've read through SDB explanations in several manuals but haven't found the explanation as to why this is happening. We have a Cobol program with record length 200, and the developer inadvertently omitted the BLOCK CONTAINS 0 RECORDS clause which according to the Cobol manual says the file is supposed to be unblocked. Developer runs the program in batch using a DD card like this for the unblocked dataset. //VSF DD DSN=TEST.DATASET.NAME, // DISP=(NEW,CATLG,DELETE), //* UNIT=VTS, // UNIT=SYSDA, // SPACE=(CYL,(5,20),RLSE), // DCB=MDCB.TEST.DATASET.NAME The only DCB information provided is in the MDCB statement which looks like this: % XT Device Dsorg Recfm Lrecl Blksz ---------------------------------------------- MDCB.TEST.DATASET.NAME 0 ? 0 3390 FB 200 0 Sorry for the lack of formatting, BLKSIZE=0, LRECL=200, RECFM=FB. If he runs his job with the DD card as above, going to an SMS managed dataset, he gets half track blocking. If he runs it changing it to UNIT=VTS, he gets an unblocked dataset, and if he runs it against DASD with an unmanaged dataset name, he also gets it unblocked. Definitely makes it look like something in the SMS configuration, however, our SMS dataclas that this dataset falls under does not specify to use SDB that I could find. So my questions are how to explain what's happening here? Why does the MDCB specification of SDB seem to override the Cobol program in the case of the SMS managed dataset but the Cobol program overrides the MDCB for the non-SMS datasets? TIA, Rex ---------------------------------------------------------------------- The information contained in this message is confidential, protected from disclosure and may be legally privileged. If the reader of this message is not the intended recipient or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any disclosure, distribution, copying, or any action taken or action omitted in reliance on it, is strictly prohibited and may be unlawful. If you have received this communication in error, please notify us immediately by replying to this message and destroy the material in its entirety, whether in electronic or hard copy format. Thank you. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
