You can specify one or more of the following Storage Management
Subsystem (SMS) classes to manage characteristics that are associated
with or assigned to data sets.
Data class is an SMS construct that an installation can define
to control data set allocation attributes used by SMS for the creation
of data sets. An installation can override all or part of an SMS DATA
CLASS definition by using FTP.DATA statements. Note that there is
an order of precedence for dynamic allocation. (See Data set attributes for
more information on the precedence.) The fields listed are available
attributes that serve as a template for allocation. Each is optional
and is overridden by any explicit specification of FTP-allocation
variables. Except for the DSNTYPE and EATTR fields, the listed variables
can be overridden by a model DCB (DCBDSN).
Variable
FTP.DATA statement
directory blocks
DIRECTORY
data set name type
DSNTYPE
extended attributes
EATTR
logical record length
LRECL
primary space
PRIMARY
record format
RECFM
retention period
RETPD
secondary space
SECONDARY
pds type
PDSTYPE
Note: If either primary or secondary space is explicitly
specified, the primary and secondary values from data class are not
used.
Management class (MGMTCLASS) is an SMS construct that determines
DFHSM action for data set retention, migration, backup, and release
of allocated but unused space. Management class replaces and expands
attributes that otherwise would be specified. That is, management
class might override any other specification of retention period.
Storage class (STORCLASS) is a list of storage performance and
availability services requests for an SMS-managed data set that SMS
attempts to honor when selecting a volume or volumes for the data
set. It might conflict with an explicit specification of volume and
unit. If storage class is used, volume and unit should not be specified.