Resource measurement facility (RMF)

The resource measurement facility (RMF) collects system-wide data that describes the processor activity (WAIT time), I/O activity (channel and device usage), main storage activity (demand and swap paging statistics), and system resources manager (SRM) activity (workload).

RMF is a centralized measurement tool that monitors system activity to collect performance and capacity planning data. The analysis of RMF reports provides the basis for tuning the system to user requirements. They can also be used to track resource usage.

RMF measures the following activities:
  • Processor usage
  • Address space usage
  • Channel activity:
    • Request rate and service time per physical channel
    • Logical-to-physical channel relationships
    • Logical channel queue depths and reasons for queuing
  • Device activity and contention for the following devices:
    • Unit record
    • Graphics
    • Direct-access storage
    • Communication equipment
    • Magnetic tapes
    • Character readers
  • Detailed system paging
  • Detailed system workload
  • Page and swap data set
  • Enqueue
  • CF activity
  • XCF activity
RMF allows the z/OS® user to:
  • Evaluate system responsiveness:
    • Identify bottlenecks. The detailed paging report associated with the page and swap data set activity can give a good picture of the behavior of a virtual storage environment.
  • Check the effects of tuning:
    • Results can be observed dynamically on a screen or by postprocessing facilities.
  • Perform capacity planning evaluation:
    • The workload activity reports include the interval service broken down by key elements such as processor, input/output, and main storage service.
    • Analysis of the resource monitor output (for example, system contention indicators, swap-out broken down by category, average ready users per domain) helps in understanding user environments and forecasting trends.
    • The post-processing capabilities make the analysis of peak load periods and trend analysis easier.
  • Manage the larger workloads and increased resources that MVS™ can support.
  • Identify and measure the usage of online channel paths.

For more information about RMF, see the IBM® Redbooks® publication ABCs of z/OS System Programming and z/OS Resource Measurement Facility (RMF) User's Guide.