SYSABEND, SYSMDUMP, and SYSUDUMP DD statements

Purpose: Use a SYSABEND, SYSMDUMP, or SYSUDUMP DD statement in a job step to direct the system to produce a dump. The system produces the requested dump:
  • If the step terminates abnormally.
  • If the step starts to terminate abnormally, but system recovery procedures enable the step to terminate normally.
The dump DD statements for requesting dumps are:
SYSABEND DD statement
Produces a dump of user and system areas; this dump contains all the areas dumped in a SYSUDUMP, plus:
  • The local system queue area (LSQA), including subpools 229, 230, and 249
  • The input/output system (IOS) control blocks for the failing task.

The dump is formatted, so that it can be printed directly.

SYSMDUMP DD statement
Produces a dump of the system areas and the program’s address space. The dump is unformatted and machine-readable. It must be processed by the interactive problem control system (IPCS) and therefore should not be directed to SYSOUT. System-determined BLKSIZE is supported for SYSMDUMPs. If you want to control the BLKSIZE for compatibility with tools developed for earlier releases of z/OS®, add the following DCB attributes to your SYSMDUMP DD statement.
RECFM=FB,LRECL=4160,BLKSIZE=4160
SYSUDUMP DD statement
Produces a dump of user areas. The dump is formatted, so that it can be printed directly.

The dump contents are as described only when the installation uses the IBM®-supplied defaults for the dumps. The contents of these dumps can be set during system initialization and/or can be changed for an individual dump in the ABEND macro instruction, in a CHNGDUMP command, and by a SLIP command. For details, see z/OS MVS Initialization and Tuning Guide.

Dumps are optional; use a dump DD statement only when you want to produce a dump.

References: For information on how to interpret dumps, see z/OS MVS Diagnosis: Tools and Service Aids.