DB2 storage groups are a set of volumes on disks that hold the data sets in which tables and indexes are stored.
The description of a storage group names the group and identifies its volumes and the VSAM (Virtual Storage Access Method) catalog that records the data sets. The default storage group, SYSDEFLT, is created when you install DB2.
Within the storage group, DB2 does the following actions:
Allocates storage for table spaces and indexes
Defines the necessary VSAM data sets
Extends and deletes VSAM data sets
Alters VSAM data sets
All volumes of a given storage group must have the same device type. However, parts of a single database can be stored in different storage groups.
DB2 can manage the auxiliary storage requirements of a database by using DB2 storage groups. Data sets in these DB2 storage groups are called DB2-managed data sets.
These DB2 storage groups are not the same as storage groups that are defined by the DFSMS storage management subsystem (DFSMSsms).