The VOL1 label is usually created by the EDGINERS or IEHINITT utility programs, or a user's program when the volume is first received at the installation. At that time, a permanent volume serial number is assigned to the volume, physically posted on the volume, and recorded in the VOL1 label.

The IBM-supplied utility programs EDGINERS or IEHINITT write the following labels in ASCII code:

1. A VOL1 label with the volume serial number, accessibility code, and owner identification that you specify. You cannot specify any other fields of the VOL1 label.
2. A dummy HDR1 label with '0001' in the file section number, file sequence number, and generation number fields; "IBMZLA" in the system code field; and a space in the accessibility field (allowing unlimited access). Reserved fields contain zeros, with a leading space in the date fields.
3. A tape mark.

A tape initialized with these labels should not be confused with an Version 3 or Version 4 tape, which requires one data set (the data set can be empty).

Version 3 or Version 4 standards require label symmetry around an empty data set when a volume is initialized. The labels written by EDGINERS and IEHINITT are accepted by the system routines that produce symmetrical labels. The HDR1 label is updated with system data, the single tape mark is overwritten with a HDR2 label containing data set characteristics, and a tape mark is written to complete the beginning-of-volume and beginning-of-file label groups. A set of trailer labels are written when the data set is closed, even if no data was written in the data set.

The IEHINITT utility program can write a VOL1 label on a labeled, unlabeled, or blank tape; it makes no checks to see what data, if any, exists on the tape. Therefore, IEHINITT does not check for password or RACF security protection; it does not create, modify, or delete RACF profiles of RACF-defined volumes. However, the IEHINITT utility does call Security Authorization Facility (SAF), which may result in a RACF call for tape volumes in an ATLDS. The IEHINITT utility can create either Version 3 or Version 4 tape labels. Detailed procedures for using the program are described in z/OS DFSMSdfp Utilities.

The EDGINERS utility program validates the mounted volume before writing a VOL1 label on a labeled, unlabeled, or blank tape. DFSMSrmm uses RACF to protect its resources with RACF profiles. DFSMSrmm also uses RACF to control actions that are taken on RACF tape profiles through the RMM parmlib option TPRACF. DFSMSrmm can also provide control of RACF at the volume pool level. It can also be used to create Version 3 or Version 4 tape labels. For details on how to do this, see thez/OS DFSMSrmm Implementation and Customization Guide.

Methods other than the EDGINERS or IEHINITT utility programs can be used to write VOL1 labels. You can use a card-to-tape program, or the system programmer can replace the IBM-supplied volume label editor routine with one that writes VOL1 labels. See ISO/ANSI volume label verification and editor routines for more information. On some old models of tape drives that use reels, some data or a tape mark should already exist on the tape; otherwise, the tape control unit may read through the entire reel of blank tape looking for a record or tape mark.

If you request output to the first data set on a Version 3 or Version 4 output volume (AL, AUL), and the tape that you are allocated is recorded in the wrong density and cannot be read or in the wrong ISO/ANSI version level, then the open or EOV routine can rewrite the VOL1 label in the density or version you specify.

This allows you to make nonspecific requests for output tapes and allows the operator to mount any available scratch tape. However, if the system-wide RACF tape protection option has been specified, then the volume is rejected because it cannot be verified that it is not a RACF-protected volume.

If you request output to any data set other than the first data set on the volume and a density or a version conflict occurs, then all further processing is done in the density or version of the existing VOL1 label (unless the IBM-supplied volume label editor routines are replaced with installation-written routines that do otherwise).

If you request an output volume for an Version 3 or Version 4 labeled (AL, AUL) tape and the mounted volume is an NL, NSL, SL, or SUL tape, then the open or EOV routine creates a VOL1 label after checking authorization for access and the expiration date. The routine sends a message to the console operator requesting serial number and owner information (see Figure 1, Fields 3 and 7). The label anomaly exit, volume label editor exit and DFSMSrmm can optionally prevent the creation or the destruction of standard labels.

The system programmer can indicate whether to create a Version 3 or Version 4 label by specifying a parameter in the DEVSUPxx PARMLIB member. For details see z/OS MVS Initialization and Tuning Reference.