Tiered storage

The M4002 family of Integrated Analytics System, including support for multi-rack configurations and optional tiered high-capacity disk storage, is fully supported from IAS 1.0.7.0. 

Note: This functionality is not available on customer-supplied rack M4002-001 model. For more information on this model, see Integrated Analytics System M4002-001 model overview.
Tiered storage provides possibility to optimize and manage warehouse storage. Various groups of data can have different access performance requirements. There are two different tiered storage groups, one for hot (frequently accessed data) and one for cold (archived, less often accessed) type of data. Hot data is assigned to a table space in storage group with fast devices, while cooler data is stored on slow, less-expensive storage.
  • Hot storage tier (based on Flash) is the primary tier. IBMSTOGROUP is the default storage group and USERSPACE1 is the default table space.
  • Cooler storage tier (Flash+HDD) is the additional tier. There’s SG_COOL storage group and TS_COOL table space defined.

For more information on the IAS hardware building blocks, see Rack-provided models hardware.

You can assign automatic storage table spaces to the storage groups, based on which table spaces have hot or cold data. Old data is moved from hot to cold storage devices automatically by Db2® (range partitioning process). You can also manually reassign a table space to a different storage group by using the ALTER TABLESPACE statement.

Advantages of tiered storage:
  1. Storage capacity is increased by adding additional storage to the infrastructure.
  2. Automatic management by multi-temperature storage - Db2 dynamically moves data across the storage groups.
  3. System performance is improved and usage of the fast storage is optimized.
  4. Cooling data is offloaded on high capacity hard disks. It can be used for backups and provides cost savings.

To monitor tiered storage you can run the ap hw command, which lists all of the hardware devices, including Disk Storage Node. To view your cool data file systems, use ap df and ap fs commands. They list coolXXXX file systems from tiered storage.