Reduce demand on system resources and improve performance
These are some areas in which you can make changes to reduce demand on system resources and improve performance:
Collection controls
The collection controls parameters control the frequency of data collections for cached volumes and control units. They also control whether cache collection is enabled or disabled.
Application collection intervals
The application collection interval parameters control how often OMEGAMON® for Storage on z/OS® rebuilds the list of volumes and data sets of the applications that it monitors.
Response time collection intervals
The response time collection interval parameters control how often response time statistics for direct access storage device (DASD) volumes are collected.
Space collection frequency
The space collection frequency parameters control how often OMEGAMON for Storage on z/OS collects space and fragmentation statistics for direct access storage device (DASD) volumes.
Write parameters for the persistent data store
The historical collection parameters determine whether OMEGAMON for Storage on z/OS writes information about the direct access storage devices (DASD) and data sets that it monitors toIBM® Tivoli® Enterprise Monitoring Server persistent data store (PDS) at the end of each Resource Measurement Facility™ (RMF™) interval.
To improve performance, you can disable the writing of information to IBM Tivoli Enterprise Monitoring Server persistent data store.
Direct access storage device statistics collection
The collection controls parameters control how cache, response time, and space and fragmentation statistics about direct access storage devices are recorded on the System Management Facilities (SMF).
Space and fragmentation statistics collection
The DASD space exclusion list parameters control the exclusion of volumes from data collection. To optimize the collection of cache statistics, designate a single LPAR to collect statistics. See Optimizing the collection of cache controller and DASD space statistics.
Exclude volumes from the collection of statistics
You can exclude volumes from the collection of space and fragmentation statistics.
Response time and cache statistics collection
The collection controls parameters select a monitoring method for response time and cache statistics collection.
Collection of information for the persistent data store
You can control the recording of information to the persistent data store of the IBM Tivoli Enterprise Monitoring Server. If historical information is recorded to the persistent data store, you can view it online.
Data stores, which can contain one or more data sets, can use either of these processes:
- Switching
- Wrapping
- Switching
- Switching applies to multiple data sets and it occurs when a data set becomes full. When the data set becomes full, recording stops. It resumes recording with the next empty data set. When recording begins on the last empty data set, the data set containing the oldest data is emptied. This ensures that space is available for switching so that recording continues when the last data set fills.
- Wrapping
- Wrapping applies to single data sets and occurs when the data set becomes full. New records replace the oldest records in the data set. The oldest records and their associated indexes must be located and deleted before the new records are inserted. Because of this, wrapping can have a negative impact on system performance.