In data class

With SMS, the system obtains information about the attributes of a data set from the data class for the data set.

In many cases, the attributes defined in the data class selected by an installation-written automatic class selection (ACS) routine are sufficient for the data sets you create with DD statements.

However, you can specify the name of a data class on the DATACLAS parameter for a new data set. (Note that an ACS routine can override the data class that you specify.)

The storage administrator at your installation defines the names of data classes and their data set attributes. To view a list of data class names and their attributes, use the Interactive Storage Management Facility (ISMF).

You can also override individual data set attributes. Any data set attributes you specify on the following parameters override the corresponding attributes in the data class for the data set.

RECORG (record organization) or RECFM (record format
LRECL (record length)
KEYLEN (key length
KEYOFF (key offset)
DSNTYPE (data set type, PDS or PDSE)
AVGREC (record request and space quantity)
SPACE (average record length, primary, secondary, and directory quantity)
RETPD (retention period) or EXPDT (expiration date)
VOLUME (volume-count

Examples

//DD5  DD  DSNAME=DESIGNA.PGM,DISP=(NEW,KEEP)
//DD6  DD  DSNAME=DESIGNB.PGM,DATACLAS=PGM5,DISP=(NEW,KEEP)
//DD7  DD  DSNAME=DESIGNC.PGM,DATACLAS=PGM5,LRECL=1024,DISP=(NEW,KEEP)