Real time statistics
The Real Time Statistics views provide current performance information about DASD device, channel, and I/O subsystem activity.
These views are based on the RMF/CMF API and contain additional fields to indicate the current status of the volume.
Real time statistics require one of the two following services:
- For RMF users, RMF along with a Monitor I session needs to be running.
- For CMF users, the CMF MONITOR Extractor needs to be running.
Data frequency is dependent on the collector. The performance statistics for the I/O Queuing Activity view are averaged over the length of the current CMF EXTRACTOR or RMFMON I recording interval. For example, if the interval is four minutes old, the statistics are averaged for the last four minutes. The actual statistics are recalculated each recording interval cycle. Typically, a recording interval cycle is one to five seconds, depending on how RMF or CMF is set up.
To access real-time statistics on storage resources, you first select a data type, such as volume response time. From the resulting list of resources, you can drill down to an individual resource, such as a specific volume. Selecting a resource produces a more detailed report about the resource or accesses an easy (EZCmd) menu that provides additional performance options.
The following table summarizes each real-time statistics option and its corresponding SETSRM keywords, action line commands, and EZCmd menus.
Real-time statistics options
Menu option | Description | SETSRM keywords | Action line commands | EZCmd menu |
|---|---|---|---|---|
Channel Activity | Advances to the MCHAN view. This view provides a listing of channel activity and performance for all online channels; for example, the percentage of time that the channel is busy, both numerically and graphically. You can examine channels with excessive amounts of busy time for possible performance degradation problems. The Channel Activity report calculates statistics by using deltas that have occurred since you pressed Enter. Therefore, you should wait a few seconds before pressing Enter, especially if the channel does not show much activity. | None | None | None |
I/O Queuing | Advances to the MIOQ view. This view provides a listing of all online LCUs and associated channels that have had activity during the current CMF or RMF recording interval. Use this view to help identify I/O queuing bottlenecks in your DASD/IO configuration. | None | None | None |
RAID EMC Directors | Advances to the REDIR view. This view displays all directors across all EMC Symmetrix devices. The view includes all installed directors, regardless of volume definition. | None | D Devices DET Detail P Physical disks V Volumes | None |
ENQ/Reserve Activity | Advances to the MRES view. This view displays all outstanding RESERVE requests that have been made against the serially reusable resources in your system. Use this view to monitor and resolve resource control contention. | None | None | None |
ENQ Activity | Advances to the MENQ view. This view displays information on the contention that exists for all serially reusable resources in your system. Use this view to monitor and resolve resource control contention. | None | None | None |
Volume Response Time | Advances to the VOLPRRT view. This view displays average response time statistics for the volumes in your system, including queue time, busy time, and disconnect time. | VOLUME PHY GROUP TYPE INTERVAL | EZVOL | |
Volume Activity | Advances to the VOLPRA view. This view displays device addresses and the average volume response times, queue times, connect times, and identification information about the volumes in your system. | VOLUME PHY GROUP TYPE INTERVAL | EZVOL | |
Physical Disk Response | Advances to the PHYPRRTZ view. This view displays detailed response-time statistics and identification information about the physical disks in your system. | VOLUME PHY GROUP TYPE INTERVAL | EZPHY | |
Physical Disk Activity | Advances to the PHYPRAZ view. This view displays average response times, queue times, connect times, and identification information about the physical disks in your system. | VOLUME PHY GROUP TYPE INTERVAL | EZPHY | |
Subsystem Response | Advances to the SSPRRTZ view. This view displays average response times, queue times, connect times, and identification information about the subsystems in your system. | VOLUME PHY GROUP TYPE INTERVAL | EZSS | |
Subsystem Activity | Advances to the SSPRAZ view. his view displays average response times, queue times, connect times, and identification information about the subsystems in your system. | VOLUME PHY GROUP TYPE INTERVAL | EZSS |