page of GC20-1807-7 As Updated April 1, 1981 by TNL GN25-0829 your viLtual machine cannot continue, it terminates and, in some cases,
attempts to issue a dump. In the VM/370 environment, the problem proq-r-am-dum-palwa-ys- goes - t-othe- v-irtllal- _printer. De-ItendiJ)_q installation operating procedures, the virtual machine operating system
dump may also go to the virtual printer. A CLOSE must be issued to the
virtual printer to have either dump print on the real printer.
The third type of dump occurs when the CP system cannot continue.
The CP abnormal termination dumps can be directed to a printer or tape
or be dynamically allocated to DASD. If the dump is directed to a tape,
the dumped data must fit on one reel of tape. Multiple tape volumes are
not supported by VM/370. The historical data on the tape is in print
line format and can be processed by user-created programs or via CMS commands. specify the output device for CP abend dumps with the CP SET command. When the CP abend dump is sent to a disk, use the CMS VMFDUMP command
to print the dump on the real printer. Use the VMFDUMP command to format and print a current or previous VM/370 system abend dump. Specify VMFDUMP to obtain a complete formatted, hexadecimal printout. When the dump has been printed, one of two messages will be printed. DUMP FILE - DUMP xx - PRINTED AND KEPT
-- or -- DUMP FILE - DUMP xx -PRINTED AND ERASED. HOW TO PRINT A CP ABEND DUMP FROM TAPE When the CP abend dump is sent to a tape, the records are 131 characters
long, unblocked, and contain carriage control characters.
To pLint the tape, first make sure the tape drive is attached to your
system. Next, define the printer and tape file.
FILEDEF ddname1 PRINTER (RECFM FM LRECL 131)
FILEDEF ddname2 {TAP2} (DEN 1600 RECFM U LRECL 132) TAP1 Then use the MOVEFILE command to print the tape: MOVEFILE ddname2 ddname1
An extended form of the VMFDUMP command may be used via the facilit.les cit IPCS (In-teracti-v-e-- Problem Cont.rolSystem)- by- Field
EnqineeLing Program Systems Representatives, and by installation system
programmers. For information on IPCS, refer to the publication !K/31g­ (lgcS) Part 1. Debugging with VM/370 45

April 1, 19S1 Reading CP Abend Dumps
Two types of printed dumps occur when CP abnormally ends, depending upon
the options specified in the CP SET DUMP command. When the dump is
directed to a direct access device, VMFDUMP must be used to format and
print the dump. VMFDUMP formats and prints: • Control blocks • General registers • Floating-point registers • Control registers • TOD Clock • Processor Timer • Storage • If in attached processor mode, formats and prints both PSAs' storage
Storage is printed in hexadecimal notation, eight words to the line,
with EBCDIC translation at the right. The hexadecimal address of the
first byte printed on each line is indicated at the left.
If the CP SET DUMP command directed the dump to
the printed format of the dump is the same as with
the control blocks are not formatted and printed.
attached processor, all of the registers, etc.,
abending processor. Also, each PSA is printed
storage.
tape or the printer, VMFDUMP, except that
If the system was an
are printed for the
before printing main When the Control Program can no longer continue and abnormally
terminates, you must first determine the condition that caused the
abend, and then find the cause of that condition. You should know the
structure and function of the Control program. "Part 2: Control Program (CP)" contains information that will help you understand the major
functions of CP. The following discussion on reading CP dumps includes
many references to CP control blocks and control block fields. Refer to VMLJ1Q Control Block 1Qgic for a description of the CP control blocks. Figure 9 shows the CP control block relationships.
Also, you will need the current load map for CP to be able to identify
the modules from their locations. REASON FOR THE ABEND
Determine the immediate reason for the abend. You need to examine
several fields in the PSA (prefix Storage Area), to find the reason for
the abend. In a uniprocessor system, the PSA is in locations 0 to 4095. In an attached processor system, each processor has its own PSA. 1. Examine the program old PSi and program interrupt code to find
whether or not a program check occurred in CP. The program old PSW (PROPSW) is located at X'2S' and the program interrupt code (INTPR) is at X'SE'. If a program check has occurred in supervisor mode,
use the CP system load map to identify the module. If you cannot
find the module using the load map, refer to "Identifying a
Pageable Module." Figure 47 in "Appendix A: System/370 Information" describes the format of an Extended Control PSi. 46 VM/370 System Programmeris Guide