At tape mount time, DFSMSrmm performs additional checking, which might result in a tape being rejected. See z/OS DFSMSrmm Implementation and Customization Guide for information about DFSMSrmm tape mount validation rules.

DFSMSrmm issues a tape rejection message to explain why the tape was rejected and to help you decide what to do next. If a tape is rejected for a specific volume request, the user's job ends abnormally with a system completion code, such as x13, x14, or x37. The user receives a message that indicates the reason for the rejection, and the user can refer to the message explanation for help in solving the problem. When you are running DFSMSrmm in warning mode, DFSMSrmm can issue up to two sets of messages when a volume is being rejected.

DFSMSrmm can reject specific mount requests depending on the OPTION BLP(NORMM/RMM) that is specified in the EDGRMMxx parmlib member.

For a specific mount request of a volume not defined to DFSMSrmm, the volume may be rejected, depending on the installation options. When PRTITION or OPENRULE are used, a volume is rejected if the applicable OPENRULE action is REJECT. When REJECT commands are used, an undefined volume is rejected only if the REJECT option in effect is either REJECT ANYUSE(*) or REJECT OUTPUT(*). The job then ends abnormally.

If a tape is rejected for a non-specific volume request, the mounted tape is unloaded and the system mount message is reissued. File the rejected tape on a separate shelf until the reason for its rejection can be determined. Usually a tape is rejected because of a mismatch of user JCL specifications, tape header labels and DFSMSrmm control data set data. In most cases, you must obtain a listing of the volume header labels to provide the tape librarian with sufficient diagnostic information. Use JES3 Tape Display DSP, MVS/DITTO, or an equivalent to get this information.

See z/OS DFSMSrmm Implementation and Customization Guide for more information on the type of checking DFSMSrmm performs when mounting tape volumes.