CSDDISP

The CSDDISP system initialization parameter specifies the disposition of the data set to be allocated to the CICS® system definition data set (CSD).

The CSDDISP system initialization parameter is effective only on a CICS cold or initial start. On a warm or emergency restart, file resource definitions for the CSD are recovered from the global catalog. If no Job Control Language (JCL) statement for the CSD exists when it is opened, dynamic allocation of the CSD using this disposition takes precedence over the open. If a DD statement exists in the JCL of the CICS startup job, it takes precedence over this disposition. For information about setting up the CSD, see Setting up the CICS system definition data set. For information about how CICS starts and stops, their implications, and the actions that are required to handle them, see Administering CICS operations.

A set of system initialization parameters configure the CSD. The names of all these system initialization parameters start with CSD. For example, CSDACC, CSDBKUP. To get the full list of system initialization parameters and their functions, see The system initialization parameter descriptions and summary. The system initialization parameters that are used to define the CSD are interdependent. For more details, see Defining CSD attributes.

Defining CSDDISP

You can define the CSDDISP system initialization parameter in the following ways:

In the PARM parameter of the EXEC PGM=DFHSIP statement.
In the SYSIN data set of the CICS startup job stream.
Through the system console.
In the DFHSIT macro.

Values for CSDDISP

CSDDISP={OLD|SHR}

Valid values for the CSDDISP system initialization parameter are as follows:

OLD: OLD is the default value for CSDDISP. The disposition of the CSD is set to OLD which indicates that the data set exists beforehand and the job requires exclusive use of it.
SHR: The disposition of the CSD is set to SHR which indicates that the data set exists and other jobs can access it simultaneously.