Starting the Db2 subsystem

During the process of enabling data sharing, start the Db2 subsystem after you define Db2 to z/OS.

Procedure

To start Db2:

  1. Start Db2 from the z/OS® console.
    The simplest form of the following command is: 
    -DSN1 START DB2
    where -DSN1 is the subsystem command prefix that you defined for Db2.

    When you issue the START DB2 command with this command format, Db2 uses the subsystem parameter module that is specified in the ssnmMSTR start-up JCL procedure in SYS1.PROCLIB.

    If you need to change the name of the subsystem parameter module, you can edit the ssnmMSTR JCL member in SYS1.PROCLIB. Alternatively, you can override the default subsystem parameter module name by using the PARM option, as follows: 
    -DSN1 START DB2,PARM(DSNZPxxx)

    If you have not run job DSNTIJRT, and the administrative task scheduler starts, the administrative task scheduler issues error message DSNA679I to report SQLCODE -805 until you run job DSNTIJRT. The administrative task scheduler starts if you specified an address space procedure name in the ADMIN SCHEDULER field on installation panel DSNTIPX.

    If Db2 starts successfully, some or all of the following address spaces start, where ssnm is the Db2 subsystem name.
    • The system services address space (ssnmMSTR)
    • The database services address space (ssnmDBM1)
    • The IRLM address space (irlmproc), where irlmproc is the IRLM procedure name
    • Possibly, the DDF address space (ssnmDIST)
    • Possibly, the administrative task scheduler stored procedure address space (ssnmADMT)
    If Db2 starts successfully, the series of RESTART messages that you receive concludes with these two messages: 
    DSNR002I   RESTART COMPLETED
DSN9022I   DSNYASCP '-DSN1 START DB2' NORMAL COMPLETION

    When you start Db2 13 for the first time, Db2 issues message DSNT501I with reason code 00C900A6. This message is expected. When you run job DSNTIJTC, which is required to complete the tailoring of the Db2 catalog, the cause of this message is corrected. Job DSNTIJTC is described in a later installation step.

    After you start Db2, identify unusual conditions for databases with the command: 
    -DSN1 DISPLAY DATABASE(*) SPACENAM(*) RESTRICT

    If Db2 does not start successfully, it usually abends with a reason code that indicates where the error occurred. To find the error, check the set of definitions for the associated resource. Ensure that the DSNTIJID, DSNTIJIE, DSNTIJIF, DSNTIJIN, and DSNTIJUZ jobs ran correctly. Also, verify that the subsystem parameter member that you specified (or allowed by default) when you started Db2 is the one that is built by job DSNTIJUZ. Check the JCL for the Db2 startup procedure.

    If you use distributed data facility, you must define VTAM® before DDF can start. However, you do not need to have TCP/IP configured to start DDF. In addition, transactions such as those from DDF or CICS® may fail because work files have not yet been defined.

  2. Optional: Start TSO.
    After Db2 starts, it is available to TSO. If you want to use the TSO SUBMIT command to do housekeeping and installation verification, you must start TSO (if it is not already started).