The IBM® standard volume label (VOL1) is 80 characters in length. The system uses it to identify the tape volume, tape volume owner, and security of the tape volume's contents. It is always the first block of data on the tape volume if the tape is a standard labeled tape.
| Offset | Data type | Length | Contents |
|---|---|---|---|
| 0 | Character | 3 | Label identifier |
| 3 | Character | 1 | Label number |
| 4 | Character | 6 | Volume identifier (Volume Serial Number) |
| 10 | Character | 1 | Volume access (security) |
| 11 | Character | 5 | VTOC Pointer (not used) |
| 16 | Character | 21 | Reserved |
| 37 | Character | 14 | Owner Name and Address Code (Owner identifier) |
| 51 | Character | 29 | Reserved |
The program records the volume label in EBCDIC.
The contents and function of each of the fields is described below.
The characters VOL identify this label as a volume label. The system reads this field to verify that it mounts a standard labeled tape. The system also verifies that this label is a volume label. The system writes this field to the tape when you use the Initialize Tape (INZTAP) command and specify the new volume (NEWVOL) parameter.
The relative position of the label within a set of labels of the same type. The label number is always 1 for the IBM standard volume label.
A unique identification code to identify the logical tape volume. The system writes the value that is specified for the new volume (NEWVOL) parameter when you use the Initialize Tape (INZTAP) command. For media library devices, the program recommends that you match the logical volume identifier with the external bar code identifier on the cartridges. The value can range from 1 to 6 alphanumeric characters (left-aligned and padded with blanks if less than 6). The alphanumeric character set includes A-Z, 0-9, @, $, and #. If a program specifies a value for a command in the VOL parameter, the system verifies this field to match the specified value.
The program considers the volume secure (from processing) if the volume security field is a blank, character zero, or hex zero. *SECOFR authority can process the secured volumes.
Not used by i5/OS™.
The owner identifier of the tape volume. The system writes a value to this field when you use the OWNER parameter on the Initialize Tape (INZTAP) command. The purpose of the field is to write the owner identifier of the volume or to write information about the contents of the volume.