IKJ56542I   EXEC FILE I/O ERROR - jobname,stepname,devicenumber,devicetype,ddname,operation,errordesc,trackaddr,QSAM

There is a file I/O error of the type denoted by errordesc. These are the fields:

jobname - Name of the current job. This is your TSO identifier.

stepname - Name of the current job step.

devicenumber - Four-hex-digit device number. It uniquely defines the device on the system. It is in the primary subchannel set.

deviceclass - Class of the device. "D" represents DASD, "T" represents tape, "U" represents unit record, and "*" represents "other".

ddname - Name of the DD in the logon procedure, background JCL or dynamic allocation.

operation - Name of the macro that failed, such as GET or PUT.

errordesc - Fifteen-character summary of the hardware failure.

trackaddr - If the device is DASD, this is the location of the failing block and the format is bbcchhr, where bb is "0000" and cchhr is the cylinder, track and record numbers in hex. If it is a compressed format data set, this is the relative block number of the compressed failing block in the data set. If it is a z/OS® UNIX file, then this is the hexadecimal offset into the file to the failure point.

If any of the above information is not available, that field will contain asterisks. For more information about the above variables, see the description of the SYNADAF macro in z/OS DFSMS Macro Instructions for Data Sets.