When an abnormal condition occurs, control first passes to the DCB abend user exit routine, if its address is provided in the DCB exit list. If a DCB abend user exit routine is not provided, or if it requests immediate abnormal termination of the task, the system passes control to IFG0199I. For a description of the DCB exit list and the DCB abend user exit routine, see z/OS V2R1.0 DFSMS Using Data Sets.

The IBM-supplied IFG0199I checks the system completion code and the return code to determine whether the abend condition is the result of a tape positioning error. If the system completion code is other than 613 with return code X'08' or X'0C', IFG0199I returns control to the calling module with return code 0, indicating that abend processing should continue.

Otherwise, IFG0199I checks the counter in the 4-byte work area to determine whether an attempt to reposition the tape has been made. If not, IFG0199I provides return code 4, indicating that repositioning should be attempted. If it has, IFG0199I issues message IEC613A to the operator asking whether to attempt repositioning again.

If the operator requests another try, IFG0199I provides return code 4 to the calling module, indicating that open should rewind the tape and attempt positioning. If the operator specifies that tape positioning should not be retried, IFG0199I provides return code 0 to the calling module, and abend processing continues.

You can modify IFG0199I to perform recovery actions for other data management abend conditions. For abend codes for which you can use IFG0199I to attempt recovery, see z/OS V2R1.0 DFSMS Using Data Sets.