IBM DS8000 manual Resource Management Facility RMF, 289

SETCACHE

The DASD fast write attributes cannot be changed to OFF status on the DS8000. Figure 13-7 on page 289, displays the messages you will receive when the IDCAMS SETCACHE parameters of DEVICE, DFW, SUBSYSTEM, or NVS with OFF are specified.

SETCACHE DEVICE OFF FILE(FILEX)

IDC31562I THE DEVICE PARAMETER IS NOT AVAILABLE FOR THE SPECIFIED

IDC31562I SUBSYSTEM OR DEVICE

IDC3003I FUNCTION TERMINATED. CONDITION CODE IS 12

SETCACHE DFW OFF FILE(FILEX)

IDC31562I THE DASDFASTWRITE PARAMETER IS NOT AVAILABLE FOR THE

IDC31562I SPECIFIED SUBSYSTEM OR DEVICE

IDC3003I FUNCTION TERMINATED. CONDITION CODE IS 12

SETCACHE SUBSYSTEM OFF FILE(FILEX)

IDC31562I THE SUBSYSTEM PARAMETER IS NOT AVAILABLE FOR THE SPECIFIED

IDC31562I SUBSYSTEM OR DEVICE

IDC3003I FUNCTION TERMINATED. CONDITION CODE IS 12

SETCACHE NVS OFF FILE(FILEX)

IDC31562I THE NVS PARAMETER IS NOT AVAILABLE FOR THE SPECIFIED

IDC31562I SUBSYSTEM OR DEVICE

IDC3003I FUNCTION TERMINATED. CONDITION CODE IS 12

Figure 13-7 SETCACHE options

All other parameters should be accepted as they are today on the IBM 2105. For example, setting device caching ON is accepted, but has no affect on the subsystem.

13.2.8 Resource Management Facility (RMF)

RMF support for the DS8000 is added via an SPE (APAR number OA06476, PTFs UA90079 and UA90080). RMF is enhanced to provide Monitor I and III support for the IBM TotalStorage DS family. The ESS Disk Systems Postprocessor report now contains two new sections:

Extent Pool Statistics and Rank Statistics. These statistics are generated from SMF record 74 subtype 8:

￿The ESS Extent Pool Statistics section provides capacity and performance information about allocated disk space. For each extent pool, it shows the real capacity and the number of real extents.

￿The ESS Rank Statistics section provides measurements about read and write operations in each rank of an extent pool. It also shows the number of arrays and the array width of all ranks. These values show the current configuration. The wider the rank, the more performance capability it has. By changing these values in your configuration, you can influence the throughput of your work.

Also, new response and transfer statistics are available with the Postprocessor Cache Activity report generated from SMF record 74 subtype 5. These statistics are provided at the subsystem level in the Cache Subsystem Activity report and at the volume level in the Cache Device Activity report. In detail, RMF provides the average response time and byte transfer rate per read and write requests. These statistics are shown for the I/O activity (called host adapter activity) and transfer activity from hard disk to cache and vice-versa (called disk activity).

Chapter 13. zSeries software enhancements 289