KM5 Device Resource History attributes
The KM5 Device Resource History attribute group for near-term history. These attributes provide information about the device, as well as the time periods for operations.
Active Percent (RMF metric) The percentage of time during the report interval when the device was active. Computation is ACT% = (PEND% + CON% + DSC%).
Activity Rate (RMF metric) The rate per second that I/O instructions (SSCH, RSCH, and HSCH) to a device completed successfully. Device Activity Rate = (#I/O Instructions / (Range Time). Range Time = <data-range unit="seconds">600</data-range>
Command Response Percent (RMF metric) Command response time delay (CMR). CMR is the percentage of time during the report interval when the first command of an I/O instruction of the channel program is sent to the device until the device indicates that it accepted the command.
Connect Percent (RMF metric) Percentage of time the device was connected to a channel path to actually transfer data between the device and storage.
Control Unit Busy Percent (RMF metric) The percentage of time during the report interval when there is I/O request delay because the control unit was busy.
Control Unit Type (RMF metric) The control unit type. For example, 2107.
Device Busy Percent (RMF metric) Device busy delay (DB). The percentage of time during the report interval when the channel subsystem measured I/O request delay because the device was busy. Device Busy Percent is a component of the Pending Time Percent.
Device Number (RMF metric) The device number where the volume is mounted.
Device Type (RMF metric) The device type. For example, 33909.
Disconnect Percent (RMF metric) Percentage of time the device has an active channel program and is disconnected (not transferring data). Disconnect time includes seek time, normal rotation delay time, and extra rotation delay because the channel was busy when the device needed to reconnect.
IO Intensity (RMF metric) IO Intensity is used to examine how many milliseconds per second applications waited for the device. The value can exceed 1000, which is an indicator that the device experiences a heavy load and requires a long time to satisfy the requests. The value also includes the IOS Queue Time. If the activity rate is low (for example, less than 1 SIO/s) and the IOS Queue Time is high, the value is not meaningful. Use this measurement for devices with a considerable load (more than 2 IOs / s).
IOS Queue Time (RMF metric) The average number of milliseconds an I/O request must wait on an IOS queue before an SSCH instruction can be issued. The Queue Time value is shown to one decimal place (0.1 of a millisecond). Delay occurs when a previous request to the same subchannel is in progress.
Logical Control Unit (RMF metric) The logical control unit number.
Managed System Tivoli Enterprise Monitoring Server (TEMS) Origin Node
PAV Count (RMF metric) The number of parallel access volumes (bases and alias) which were available at the end of the reporting. If the number changed during the report interval, it is followed by an '*'. For example, 2*. If the device is a HyperPAV base device, the number is followed by an 'H'. For example, 1.2H.
Pending Percent (RMF metric) Percentage of time all I/O requests wait in the logical control unit queue (CU-HDR) before there is an available path. Pending time includes the time spent waiting for a channel, control unit, or head of string, or for the actual device (if it is a shared device that is reserved by another processor).
Recording End Time Time at the end of the RMF reporting interval for the current row of near-term historical data. The valid format is yy/mm/dd hh:mm:ss.
Recording Start Time Time at the start of the RMF reporting interval for the current row of near-term historical data. The valid format is yy/mm/dd hh:mm:ss.
Response Time (RMF metric) The average response time (in milliseconds to one decimal) that the device required to complete an I/O request.
- RMF Near Term History Active = 1
- No RMF DEVR Report Activity = 2
- RMF DDS not available = 3
Sample Period Sample period in seconds. By default, this attribute is not presented in the workspace.
SMF ID System Management Facility ID. This is the ID for the system or LPAR being monitored.
Status (RMF metric) Status. An S in the first line of this column indicates that the device was generated during system generation as a shared device.
Switch Port Busy Percent (RMF metric) The percentage of time during the report interval when there is I/O request delay because the control unit was busy.