DSN1SDMP

IBM® Support might advise you to use the IFS selective dump (DSN1SDMP) stand-alone utility. DSN1SDMP enables you to force dumps when selected Db2 trace events occur, write Db2 trace records to user-defined z/OS® data sets, or start another Db2 trace.

To ensure that you do not take action on an IFCID 4 or IFCID 5 start or stop trace record, it is good practice to add 
P4,00
DR,04,X'hhhh'
to your control statement, where hhhh is the hex representation of the IFCID that you are trying to trigger on.

Output

One intended use of this utility is to aid in determining and correcting system problems. When diagnosing Db2, you might need to refer to licensed documentation to interpret output from this utility; see Db2 13 for z/OS licensed diagnosis information.

Environment

Run DSN1SDMP as a z/OS job, and execute it with the DSN TSO command processor. To execute DSN1SDMP, the Db2 subsystem must be running.

The z/OS job completes only under one of the following conditions:

  • The TRACE and any additional selection criteria that are started by DSN1SDMP meet the criteria specified in the FOR parameter.
  • The TRACE that is started by DSN1SDMP is stopped by using the STOP TRACE command.
  • The job is canceled by the operator.

If you must stop DSN1SDMP, use the STOP TRACE command.

Authorization required

To execute this utility, the privilege set of the process must include one of the following privileges or authorities:

  • TRACE system privilege
  • SYSOPR authority
  • SYSADM authority
  • MONITOR1 or MONITOR2 privileges (if you are using user-defined data sets)
  • SQLADM authority
  • System DBADM authority
  • SECADM authority

The user who executes DSN1SDMP must have EXECUTE authority on the plan that is specified in the trace-parameters of the START TRACE keyword.

Required data sets

DSN1SDMP uses the following DD statements:

SDMPIN
Defines the control data set that specifies the input parameters to DSN1SDMP. This DD statement is required. The LRECL is 80. Only the first 72 columns are checked by DSN1SDMP.
SDMPPRNT
Defines the sequential message data set that is used for DSN1SDMP messages. If the SDMPPRNT DD statement is omitted, no messages are written. The LRECL is 131.
SYSABEND
Defines the data set that is to contain an ABEND dump in case DSN1SDMP abends. This DD statement is optional.
SDMPTRAC
Defines the sequential Db2 trace record data set that Db2 returns to DSN1SDMP. The DD statement is required only if trace data is written to an OPX trace destination. If the destination is anything other than an OPX buffer, SDMPTRAC is ignored.

Trace records that Db2 writes to SDMPTRAC are of the same format as SMF or GTF records except that the SDMPTRAC trace record headers contain the monitor header (that is mapped by DSNDQWIW). The The DCB parameters are VB, BLKSIZE=32760, LRECL=32756.

SYSTSIN
Defines the DSN commands to connect to Db2 and to execute an IFC selective dump: 
DSN SYSTEM(subsystem name)
RUN PROG(DSN1SDMP) LIB('prefix.SDSNLOAD') PLAN(DSNEDCL)
The Db2 subsystem name must be filled in by the user. The DSN RUN command must specify a plan for which the user has execute authority. DSN1SDMP dump does not execute the specified plan; the plan is used only to connect to Db2.

When no plan name is specified on the DSN RUN command, the default plan name is the program name. When DSN1SDMP is executed without a plan, DSN generates an error if no DSN1SDMP plan exists for which the user has execute authority.