Diagnostic message and trace data set (EQQDMSG)

You should allocate EQQDMSG for each dialog user. You can allocate EQQDMSG either as a SYSOUT data set or as a DASD data set. Usually only a small volume of diagnostic information exists, so an initial allocation of two tracks of DASD should be enough. If EQQDMSG is not defined, output is written to EQQDUMP.