Data presented by CMF MONITOR Online
CMF MONITOR Online is a tool that helps you manage MVS system performance. CMF MONITOR Online monitors system activity and collects information about all address spaces (TSO users, batch jobs, and Started Tasks), such as
- address space use of various system resources
- delays that each address space (job) incurs while waiting for access to these resources
- resource use and contention, identifying the delays that jobs encounter, resources that are contention bottlenecks, and jobs competing for those resources
The system resources that are monitored are physical (processors, real storage, direct access storage, and tape devices) and logical (SRM and enqueues). The following types of information appear in CMF MONITOR Online views:
- amount of delay for each workload, performance group, and job
- resources in which bottlenecks exist
- jobs contending for these resources
- jobs that are using these resources
The major resources that CMF MONITOR Online monitors and the probable reasons for delays are shown in the following table
System resource | Reason for delay |
|---|---|
device | DASD I/O queued DASD reserve disk mount pending tape I/O queued tape mount pending |
enqueue | contention for logical resources |
HSM | HSM staging data sets to a DASD volume |
processor (CPU) | waiting for the CPU |
SRM | auxiliary storage shortage real storage shortage request swaps enqueue exchange swaps exchange swaps unilateral swaps transition swaps Response Time Option (RTO) |
storage | page-in wait due to demand paging from
page-in wait due to swap page-in from
VIO page-in wait: real storage shortage |
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