That's why I wrote "for labeled tapes" rather than "for tapes". For DASD the VTOC and VTOC index are not adjacent to the data set, while the dataset label on tape is adjacent.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 עַם יִשְׂרָאֵל חַי נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of David Spiegel <[email protected]> Sent: Tuesday, February 10, 2026 8:57 AM To: [email protected] <[email protected]> Subject: Re: z/OS MVS JCL User's Guide content error External Message: Use Caution Yeah, if the Tape has a Label. Also, the Tape Label is a separate file, so the DSN is not exactly store with Dataset. On 2026-02-10 07:57, Seymour J Metz wrote: > That's a definite maybe. For labelled tapes the truncated name is stored with > the data. > > -- > Shmuel (Seymour J.) Metz > http://mason.gmu.edu/~smetz3 > עַם יִשְׂרָאֵל חַי > נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר > > > > > ________________________________________ > From: IBM Mainframe Discussion List <[email protected]> on behalf of > Mike Shaw <[email protected]> > Sent: Friday, January 30, 2026 12:16 PM > To: [email protected] <[email protected]> > Subject: z/OS MVS JCL User's Guide content error > > > External Message: Use Caution > > > Everyone, > > The sentence below appears in the z/OS MVS JCL User's Guide in all versions > from z/OS V2R1 through z/OS V3R1, in the Chapter 12 section entitled > "Identification of Data Set": > > "When creating a data set, assign a name to the data set in the DSNAME > parameter. The data set name is stored with the data set." > > That second sentence is just flat wrong. The data set name can be stored in > an F1 DSCB in the VTOC on the volume where the data set resides, and it can > be stored in a catalog, but it is never stored with the data set. > > Mike Shaw > MVS/QuickRef Support Group > Chicago-Soft, Ltd. > > ---------------------------------------------------------------------- > 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 ---------------------------------------------------------------------- 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
