This section describes features of DFSMS from the perspective of
z/OS; it does not distinguish between features added by, e.g., DFDS, and features added in the latest release of z/OS.
DFSMSdss DFSMSdss is a chargeable feature of DFSMS that can dump and restore selected data sets and selected volumes based on specifications in control statements. It is also referred to in documentation as a
data mover. DSS replaces the older DASDR and the dump/restore facilities of IEHDASDR, although the dump formats are not compatible.
DFSMSdfp DFSMSdfp replaces the older direct, index and sequential access methods, the utilities and service aids, the linkage editor, the loader and program fetch. It is the component to which new device support code is added. DFSMSdfp adds a number of loosely related facilities.
Indexed VTOC The VTOC structure inherited from
OS/360 uses records with 44 byte keys, and a sequential search using a Search Key Equal/TIC *-8 loop. The
VTOC Index (VTOCIX) is an optional data set that indexes
Data Set Control Blocks (DSCBs) and allows a faster search.
ICF catalog The Improved Catalog Facility (ICF) replaces the OS/360 Control Volume (CVOL) and the
VSAM catalog with a more resilient catalog structure.
PDSE Partitoned Data Set Extended (PDSE) is a new type of dataset that resolves several issues with the old PDS organization but that can be read and written by existing BPAM,
BSAM and
QSAM code.
System Managed Storage System Managed Storage (SMS) is a set of facilities for controlling the placement, migration and retention of datasets on direct access storage devices that is more flexible than older methods, e.g., VOL=SER specifications in JCL. Prior to SMS, the installations defined unit names during system generation, and two pools of DASD volumes, called PUBLIC and STORAGE, in a member of the system parameter library. In addition, users had to explicitly define characteristics of new datasets. With SMS, an installation can define and update several types of lists, described by IBM as ;Data Class :Data definition parameters ;Storage Class :Availability and accessibility requirements ;Management Class :Data migration, backup, and retention attributes ;Storage Group :List of storage volumes with common properties ;Aggregate Group :Backup or recovery of all data sets in a group in a single operation ;Copy Pool The installation can also define automatic class selection (ACS) rules that can test, e.g., data set name, and select list names based on installation policies and user requests. A common scenario is for the installation to write a storage group ACS routine to ignore any UNIT parameter and to select the storage group, and to write a DATACLASS ACS rule to assign a dataclass that has default DCB parameters, with both making decisions based on the data set name. When SMS is active, several new parameters are available in dynamic allocation and the DD JCL statement, e.g., DSNTYPE.
The Binder The Binder is a program similar to the linkage editor that can also manage
program objects on a PDSE library.
Remote copy and mirroring DFSMSdfp provides facilities for using several different protocols to duplicate or mirror DASD volumes to a remote location.
OAM Object Access Method (OAM) maintains a library of unstructured objects. Such objects are sometimes referred to as
BLOBs.
DFSORT DFSORT is a sort/merge utility that is part of the DFSMS family but not part of the DFSMS/MVS product.
DFSMShsm DFSMShsm, originally Hierarchical Storage Manager (HSM), 5740-XRB, and later Data Facility Hierarchical Storage Manager Version 2 (DFHSM), 5665-329, before becoming an optional component of DFSMS, is a utility for archiving and retrieving datasets. It migrates data from faster storage to less expensive storage, either based on time stamps or explicit requests. It uses DFSMSdss as a data mover.
RACF RACF is a security program that is part of the DFSMS family but not part of the DFSMS/MVS product. It includes an API called SAF that allows applications to do authentication and to check access privileges, and also includes an interface to
LDAP.
DFSMSrmm The
Removable Media Manager (DFSMSrmm) controls libraries of tapes, whether manually mounted on
tape drive or stored in an
automated tape library. == Notes ==