50 Storage Management with DB2 for OS/390
MCDB22 This Management Class is intended fortable spaces that are
allowed to migrate and require less availability than that defined
in the MCDB2M1 Management Class. This Management Class
causes migrationafter one week of inactivity and the table space
will migrate directly to level2. For example, this Management
Class can be used for Testor Development table spaces.
Table13. SMS Management Classes for DB2 Databases
6.1.5 SMS Storage Groups
SMS Storage Classes and Management Classes are combined to generate
Storage Groups. This function is performed bythe ACS routines. Table 14 on
page 51 showsthe relationship between SMS Storage Classes and the SMS
Management Classes with theSMS Storage Groups. Only those Storage Groups
required tos atisfyDB2 database requirements need to be defined.
SMS Storage Groups should be created based on availabledisk typesand data
set requirements as defined in StorageClasses and Management Classes. Only
exceptionally,for large (partitioned) table spaces and for critical table spaces,
may strict data setplacem entbe an iss ue.Only in these cases may special SMS
Storage Groups be defined.
Table15 on page 51 shows the attributes of the example SMS Storage Groups for
DB2 tableand index spaces. These are:
SGDB20 Standard Storage Group intended to satisfymost of the DB2 table
spaces and indexspaces. No DFSMShsm migration nor DFSMS
backup is required.
SGDB21 Storage Group for DB2 table spaces and index spaces that may
migrate;for example, data warehouse table and index spaces.
SGDB22 Storage Group for DB2 table spaces and index spaces that may
migrate to level2. For example, development system table and
index spaces.
SGDBFAST Storage Group forD B2 tablespaces and indexspaces requiring
performance. No DFSMShsm migration nor DFSMS backup.
SGDBCRIT Storage Group for DB2 table spaces and index spaces requiring
performance and availability. No DFSMShsm migration nor
DFSMS backup.
MCDB20 MCDB21 MCDB22
Expire after DaysNon-usage NOLIMIT NOLIMIT NOLIMIT
Expire after Date/Days NOLIMIT NOLIMIT NOLIMIT
Retention Limit NOLIMIT NOLIMIT NOLIMIT
Primary Days Non-usage 77
Level1 Days Date/Days 14 0
Command or Auto Migrate None Both Both
Backup Options NotApplicable NotApplicable NotApplicable