
Chapter 7. Practical performance management 241
Figure 7-4 Storage device: Physical view
The amount of available information or metrics depends on the type of subsystem involved.
The SMI-S standard does not require vendors to provide detailed performance data. For the
DS8000, IBM provides extensions to the standard that include much more information than
the information that is required by the SMI-S standard. Therefore, the NAPI is used.
The DS8000 interacts with the NAPI in the following ways:
Access method used: Enterprise Storage Server Network Interface (ESSNI)
Failover:
– For the communication with a DS8000, Tivoli Storage Productivit