Using SMS Data Classes

A Storage Management Subsystem (SMS) data class is a template of data set attributes (such as record length and format) that you can specify is to be used when creating a new data set. Studio Enterprise Edition enables applications running in an enterprise server to make use of SMS data classes.

Data class definitions are stored in a file that you must create using Studio Enterprise Edition. Once you have created a data class definition file in Studio Enterprise Edition you need to enable SMS support then specify the data class definition file that you want to use for an enterprise server. The following steps show how to do this:

1. Enable SMS support by setting the MF_SMS environment variable to ON.
2. Specify the data class definition file to use by performing the following steps:
   1. In the table of servers on the Home page of Enterprise Server Administration, click Edit to the left of the row for the server that you want to edit.
   2. Click the Properties tab then the General tab if they are not selected already.
   3. Specify the following in the Configuration Information field:

      MFUSERCAT_LOC=definition-file

      where definition-file is the fully-qualified location and name of the data class definition file to use.

   4. Click OK.

Once you have defined some data classes and made the data class definition file available you can refer to them using any of the following methods:

• DATACLAS parameter of a JCL DD statement
• DATACLASS parameter of a TSO ALLOCATE command
• DATACLASS parameter of an IDCAMS DEFINE command
• data class text unit (TU) of SVC 99 (DYNALLOC)

The same definitions file can be used by more than one enterprise server, ensuring consistency of data class definitions. Whenever a data class specification is missing, a default data class called MFEDFTDC is used, if it exists. This data class must exist in an enterprise server's data class definitions file for it to be available for that enterprise server.

For full information on SMS, see the DFSMSdfp Storage Administration Reference available from the IBM BookManager Server Library.