Dump formatting options

General formatting options are available for IMS and z/OS® memory dumps.

  • Offline IMS or z/OS formatting from a SYS1.DUMPxx (SDUMP) data set
  • Offline IMS or z/OS formatting from a SYSMDUMP data set
  • Online IMS or z/OS formatting directed to either a SYSABEND or SYSUDUMP SYSOUT class
  • Online z/OS formatting directed to either a SYSABEND or SYSUDUMP spinoff dump SYSOUT class

The dumping options that are in effect in an IMS environment depend on:

  • Whether the execution is an online execution or a batch execution.
  • Whether the error might terminate IMS.
  • Whether the FMTO EXEC parameter is specified.
  • Whether the SOD EXEC parameter is specified for an online execution.
    Note: This parameter is not supported in a batch execution.
  • Whether a SYSABEND, SYSUDUMP, or SYSMDUMP is chosen.
  • The z/OS dump options chosen for SDUMP, SYSABEND, SYSUDUMP, and SYSMDUMP.
  • Whether the Dump Override Table (DFSFDOT0) contains any entries. DFSFDOT0, and its relationship to the various dumps, is explained in IMS Version 15.5 Exit Routines.

FMTO options

In the following table:
  • The default is FMTO=D.
  • SYSABEND, SYSUDUMP, and SYSMDUMP are mutually exclusive.
  • z/OS formatting always accompanies IMS online formatting.
  • Spinoff dumps can occur in addition to SDUMPs.
Table 1. FMTO options and their effect on memory dumps produced.
FMTO value IMS online formatting

SYSABEND
SYSUDUMP

 z/OS online formatting

SYSABEND
SYSUDUMP

 IMS offline formatting SDUMP IMS offline formatting SYSMDUMP IMS spinoff dump

SYSABEND
SYSUDUMP
TE NT FDDL TE NT TE NT TE NT TE NT
D S — S S — Y Y S — — Y
X S — S S — Y N S — — Y
M N — N S — Y Y S — — Y
R N — N S — Y N S — — Y
T Y — Y Y — N Y Y — — Y
P Y — N Y — N Y Y — — Y
F Y — N Y — N N Y — — Y
N N — N Y — N Y Y — — Y
Z N — N Y — N N Y — — Y

SDUMPs

If SDUMP is used, be aware of these additional considerations:

  • If SDUMP is requested by the FMTO option, it is attempted first. If SDUMP is successful, no other dump (except a spinoff dump) is generated.
  • If SDUMP fails, if IMS online formatting is requested, and if a SYSABEND or SYSUDUMP DD statement is present, a dump with IMS and z/OS online formatting is generated for terminating errors.

    The formatted dump delete list (FDDL) consists of IMS module and control block names, and a dump or delete action indicator. For a module, the delete process removes storage occupied by the module. This causes the module to be omitted from the storage image portion of the dump. However, the module/save ID is printed in the dump. For a control block, the delete process similarly removes storage and storage image output if the block was successfully formatted.

  • If SDUMP fails, IMS online formatting is not requested, and a SYSABEND or SYSUDUMP DD statement is present, a dump with z/OS online formatting is generated for terminating errors.
  • If SDUMP fails and a SYSMDUMP DD statement is present, a machine readable dump is generated for terminating errors.

SYSMDUMPs

If SYSMDUMP is used, be aware of these additional considerations:

  • SYSMDUMP DD statements should be present in the IMS, DBRC, and DLISAS procedures.
  • The SYSMDUMP DD statement must specify DISP=MOD, because it is possible for multiple tasks to generate dumps during the processing of an error.
  • The SYSMDUMP data set must be refreshed (for example, scratched and reallocated) before it can be reused. If this is not done, new dumps are appended to the end of the data set and may not be accessible to the Offline Dump Formatting utility.
  • Do not use SYSMDUMP in place of SYSABEND or SYSUDUMP.

Spinoff dumps

If spinoff dumps are used, be aware of these additional considerations:

  • If a spinoff dump SYSOUT class is specified (SOD EXEC parameter in the IMS control region), a spinoff dump is generated for nonterminating errors.
  • Spinoff dumps allow the dump data set to be released to JES for immediate printing. (This can be useful when external subsystems are supported.)
  • Spinoff dumps are only generated for those tasks that do not terminate IMS.
  • If a SYSABEND or SYSUDUMP DD statement is not provided, the first dump is not printed. For subsequent dumps, the dump data set is dynamically allocated using the spinoff dump class.
  • The spinoff dump class (SOD execute parameter) should be the same as the SYSABEND or SYSUDUMP SYSOUT class.

    If the classes are different, the first dump goes to the class specified on the SYSABEND or SYSUDUMP DD statement. The dump data set is then dynamically deallocated to free the dump for printing and then dynamically reallocated using the spinoff dump class. Therefore, all subsequent dumps go to the spinoff dump class.

  • The only valid SYSABEND or SYSUDUMP DD statement parameter used for spinoff dump is the SYSOUT class. Other parameters are ignored.
  • Spinoff dumps use the default output limit established during JES definition. Incomplete spinoff dumps can result if the limit specified is too low.

z/OS dump options

To create IMS dumps that are useful in diagnosing problems, specify the proper dump options for each type of z/OS dump used for IMS.

Use the z/OS operator command DISPLAY DUMP, OPTIONS to determine the dump options currently in effect on your system.

If the current dump options do not include the options listed in this topic, the defaults that are obtained from SYS1.PARMLIB (members IEAABD00, IEADMP00, and IEADMR00) must be altered. Use the z/OS operator command CHNGDUMP to change dump options.

Table 2. z/OS dump options
Type of dump z/OS dump options
SDUMP SDUMP=(CSA,PSA,RGN,SQA,SUM,TRT,GRSQ)
SYSABEND
  • SYSABEND,SDATA=(CB,DM,ENQ,ERR,IO,LSQA,SUM,TRT)
  • SYSABEND,PDATA=(JPA,LPA,PSW,REGS,SA,SPLS)
SYSUDUMP
  • SYSUDUMP,SDATA=(CB,ERR,SUM)
  • SYSUDUMP,PDATA=(JPA,LPA,PSW,REGS,SA,SPLS)
SYSMDUMP (online system only) SYSMDUMP=(CSA,LSQA,RGN,SQA,SUM,SWA,TRT)
SYSMDUMP (batch system only) SYSMDUMP=(LSQA,RGN,SQA,SUM,SWA,TRT)

IMS online system dump options

In an online IMS environment, the following dumps are possible:

  • SDUMP to a SYS1.DUMPxx data set. SDUMP can then be formatted using the Offline Dump Formatter utility.

    This dump can be generated both for errors that cause IMS to terminate (terminating errors) and for errors that do not cause IMS to terminate (non-terminating errors).

  • SYSABEND or SYSUDUMP with IMS or z/OS formatting performed online.

    This dump is generated for terminating errors only if SDUMP fails or was not requested.

  • SYSMDUMP to a data set. SYSMDUMP can then be formatted using the Offline Dump Formatting utility.

    This dump is generated for terminating errors only if SDUMP fails or was not requested.

  • Spinoff dump to SYSABEND or SYSUDUMP with z/OS formatting performed.

    This dump is generated for non-terminating errors and can be generated in addition to SDUMP.

Online system dependent region dump options

Except for SDUMPs, the dumping options for the dependent regions are controlled by the following:

  • The spinoff dump SYSOUT class (SOD EXEC parameter in the DFSMPR and IMSFP procedures)
  • The presence or absence of a SYSABEND or SYSUDUMP DD statement in the dependent region JCL. These DD statements are mutually exclusive; provide only one.

Do not use SYSMDUMP in IMS dependent regions.

MPP, IFP, and BMP dependent regions

In the online IMS environment, the following dumps are useful for MPP, IFP, and BMP dependent regions:

  • SYSABEND or SYSUDUMP (with z/OS formatting performed online).
  • Spinoff dump to SYSABEND or SYSUDUMP (with z/OS formatting). This dump is available only for MPP and IFP dependent regions.
  • SDUMP to a SYS1.DUMPxx data set. (SDUMP can then be formatted using the Offline Dump Formatter utility.) An SDUMP is produced in the dependent region for certain IMS system errors involving DL/I or Fast Path. In this instance, the SDUMP is controlled by the FMTO specification for the control region.

Spinoff dumps in dependent regions

If spinoff dumps are used, some additional considerations are necessary:

  • Spinoff dumps allow the dump data set to be released to JES for immediate printing. (This can be useful for never-ending MPP or IFP regions.)
  • If a SYSABEND or SYSUDUMP DD statement is not provided, the first dump is not be printed. For subsequent dumps the dump data set is dynamically allocated using the spinoff dump class.
  • The spinoff dump class (SOD EXEC parameter) should be the same as the SYSABEND or SYSUDUMP SYSOUT class.

    If the classes are different, the first dump goes to the class specified on the SYSABEND or SYSUDUMP DD statement. The dump data set is then dynamically deallocated to free the dump for printing and then dynamically reallocated using the spinoff dump class. Therefore, all subsequent dumps go to the spinoff dump class.

  • The only valid SYSABEND or SYSUDUMP DD statement parameter used for a spinoff dump is the SYSOUT class. Other parameters are ignored after the first dump.
  • Spinoff dumps use the default output limit established during JES definition. Incomplete spinoff dumps can result if the limit specified is too low.
  • If the COBOL DEBUG option is used, dumps cannot be generated.

Batch system dumps

In the batch IMS environment, the following dumps are possible:

  • SYSMDUMP to a data set. (SYSMDUMP can then be formatted using the Offline Dump Formatting utility.) This dump is only generated for terminating errors.
  • SYSABEND or SYSUDUMP (with IMS or z/OS formatting performed online). This dump is only generated for terminating errors.

FMTO options for batch dumps

The FMTO options for batch dumps, and their effect on the dumps produced, are different from the FMTO options described in FMTO options. The FMTO options for batch dumps are summarized in Table 1.

When using Batch FMTO options, remember the following:

  • If a SYSMDUMP DD statement is present, a machine readable dump is generated for terminating errors.
  • If IMS online formatting is requested and a SYSABEND or SYSUDUMP DD statement is present, an IMS online formatted dump is generated for terminating errors.
  • If IMS online formatting is not requested and a SYSABEND or SYSUDUMP DD statement is present, a z/OS online formatted dump is generated for terminating errors.
  • The default is FMTO=D.
  • SYSABEND, SYSUDUMP, and SYSMDUMP are mutually exclusive.
  • z/OS formatting always accompanies IMS online formatting.
In the following table, the following codes are used:
Option
Effect on dump produced
TE
Error would terminate IMS.
NT
Error would not terminate IMS.
FDDL
Formatted dump delete list processing.
Y
Yes
N
No
—
Not applicable, or not attempted.
Table 3. Batch FMTO options
FMTO Value IMS Online Formatting SYSABEND SYSUDUMP z/OS Online Formatting SYSABEND SYSUDUMP IMS Offline Formatting SYSMDUMP
  TE NT FDDL TE NT TE NT
D Y — Y Y — Y —
X Y — Y Y — Y —
M N — N Y — Y —
R N — N Y — Y —
T Y — Y Y — Y —
P Y — N Y — Y —
F Y — N Y — Y —
N N — N Y — Y —
Z N — N Y — Y —

If SYSMDUMP is used, be aware of these additional considerations:

  • The SYSMDUMP DD statement should specify DISP=MOD.
  • If DISP=MOD is used, then the SYSMDUMP data set must be refreshed (for example, scratched and reallocated) before it can be reused. If this is not done, new dumps are appended to the end of the data set and might not be accessible to the Offline Dump Formatting utility.