Draft Document for Review February 7, 2020 3:15 pm 8464ch02_Architecture.fm GLYPH<SM590000> Data Class Each of these constructs are used by the TS7700 to determine how to manage your data.  Ideally, each construct features a matching definition within the TS7700, although default  behaviors are inherited if no match is found. You can predefine these constructs on the  TS7700 MI. For more information, see “Defining TS7700 constructs” on page 557. If  constructs are sent to the TS7700 without having predefined constructs on the TS7700, the  TS7700 creates the construct by using the currently configured default parameters for that  construct.  Tip:  Predefine your SMS constructs on the TS7700. The constructs that are created  automatically might not be suitable for your requirements. Storage Class in SMS SCs decide the following factors:  GLYPH<SM590000> Whether data is SMS-managed GLYPH<SM590000> The level of performance of a data set GLYPH<SM590000> Whether you can override SMS and place data on specific volumes  Storage Class in TS7700 Storage Group in SMS Storage Group in TS7700 Management Class in SMS Management Class in TS7700 The SC in TS7700 is used to set the cache preferences for the logical volume. This definition  is cluster-based. SGs are the fundamental concept of DFSMS. DFSMS groups disks into storage pools, so you  allocate by storage pool. Storage pools can also consist of tape volumes. This feature  enables SMS to direct tape allocations to a VTS or automated library. For tape SGs, one or  more tape libraries can be associated with them.  Connectivity is defined at the library and SG levels. If an SG is connected to specific systems,  any libraries that are associated with that SG must be connected to the same systems. You  can direct allocations to a local or remote library, or to a specific library by assigning the  appropriate SG in the SG ACS routine. The SG in the TS7700 is used to map the logical volume to a primary physical tape or cloud  pool. This definition is cluster-based. MCs are used to determine backup and migration requirements. When assigned to data sets,  MCs replace and expand attributes that otherwise are specified on job control language (JCL)  data definition ( DD ) statements,  IDCAMS DEFINE  commands, and DFSMS Hierarchical Storage  Manager (DFSMShsm) commands.  An MC is a list of data set migration, backup, and retention attribute values. An MC also  includes object expiration criteria, object backup requirements, and class transition criteria for  the management of objects.  From the TS7700 side, the MC is used for functions, such as Copy Policy, Selective Dual  Copy Pool (depending on the physical pool, this function might be used for Copy Export),  Retain Copy Mode, and Scratch Mount Candidate for Scratch Allocation assistance. This  definition is cluster-based. Chapter 2. Architecture, components, and functional characteristics  25