gtpo1mhjOperations

Stand-Alone Dump (SADUMP) Utility

The stand-alone dump (SADUMP) utility is an offline utility that can be IPLed from tape. It is used to dump main storage when a normal online dump cannot be processed because of a system hang condition.

Setup

The SADUMP utility is assembled into an object library during the system initialization program (SIP). Then, it is loaded to a nonlabeled tape using IEBGENER. See TPF System Generation for more information about SIP.

Note:
It is recommended that you use the highest format tape device available to the TPF system and to the IBM MVS system to maximize the dump tape capacity. A standard cartridge mounted on a 3480 tape device holds approximately 200 MB of data. An enhanced capacity cartridge system tape (ECCST) mounted on a 3490E tape device holds approximately 800 MB of data. A 3590 cartridge mounted on a 3590 tape device holds 10-40 GB of data.

When the tape is IPLed, the dump is written after the SADUMP program, so the tape can be reused for subsequent dumps without reloading the SADUMP object code.

Sample JCL for Creating an SADUMP Tape

The following is a sample of the JCL that you need to load the SADUMP utility to tape:

//SADLOAD EXEC PGM=IEBGENER,REGION=58K
//SYSPRINT  DD SYSOUT=A
//SYSIN     DD DUMMY
//SYSUT1    DD DSN=*OBJECT.LIBRARY*(SADUMP40),DISP=SHR
//SYSUT2    DD DSN=DUMP.TAPE,UNIT=TAPE,DISP=(NEW,KEEP),LABEL=(,NL),
//  VOL=SER=XXXXXX,DCB=(RECFM=FB,LRECL=80,BLKSIZE=80)
Note:
Replace *OBJECT.LIBRARY* with the library containing SADUMP40.

Processing Procedures

If there is a system hang condition, follow these procedures:

  1. Press the STOP key.
  2. Enter STORE STATUS from the operator control panel. This should be done from the main I-stream (the CPU from which the TPF system was IPLed).

    Even if you do not enter STORE STATUS, the dump is still performed. However, the control registers, current PSW, CPU Timer, and TOD clock comparator values are not captured. The general purpose registers are always captured.

  3. Mount and make ready the SADUMP tape on an available tape device. The available tape device must be the same format as the tape device used to create the tape.
  4. IPL the tape without the RESET or CLEAR options. The SADUMP utility then scans for the end of the SADUMP program and begins writing the content of main memory to the SADUMP tape.
Note:
The SADUMP tape must be IPLed from the same I-stream that issued the STORE STATUS so that the store status information is formatted properly by the dump postprocessor.

Normal End-of-Job

All communication with the operator is through the current PSW.

Normal End-of-Dump PSW

When the dump ends successfully, the SADUMP tape is rewound and unloaded and the TPF system is placed in a disabled wait state with the following PSW:

X'000A000000000E0D'

If the memory size exceeds the capacity of the SADUMP tape, the first tape is unloaded and the TPF system is placed in an enabled wait state (no PSW displays on the operator control panel) until you mount a second tape on the same tape device. The second tape can be any scratch tape. When the second tape is readied, the dump continues to normal end-of-job status.

Tape Mount Request PSW

If you are in doubt about the status of the dump, stop the processor and display the current PSW. The following PSW indicates that the dump is waiting for a second tape:

X'020A00000000FEED'

Abnormal End-of-Job

If the dump finds an irrecoverable error, the SADUMP tape stops without rewinding or unloading.

I/O Error PSW

The TPF system is placed in a disabled wait state and displays a PSW that contains error information in the following format:

X'000A0000'xxxxyyyy

where:

xxxx
is the operation code of the failing I/O instruction.

yyyy
is one of the following:

Unexpected System Interrupts

The TPF system is placed in a disabled wait state and displays a PSW that contains error information in the following format:

X'000A0000'xxxxxxx

where:

xxxxxxx
is one of the following PSW codes that describes the interrupt that occurred:

1111111
An external interruption

2222222
A supervisor call interruption

3333333
A program interruption

4444444
A machine check interruption

5555555
An input/output interruption.