Performance Intervals
The PerformanceManager defines performance intervals which specify the period of time between collection events, how much data will be collected, and how long the collected data will be saved.
The PerformanceManager.historicalInterval property is an array of PerfInterval objects. The following table lists the PerfInterval properties.
Level at which the Server collects data. The interval level corresponds to the performance counter level (PerfCounterInfo.level). The Server will collect data for all counters with levels that match PerfInterval.level, and for all counters with levels lower than PerfInterval.level. You can modify this property on a vCenter Server only.
The PerformanceManager uses the samplingPeriod, level, and length properties to determine its collection behavior. It does not interpret the name string. You cannot modify this property.
ESXi Server Performance Intervals
An ESXi server collects performance data for each performance counter every 20 seconds. The PerformanceManager.historicalInterval array for an ESXi Server contains a single, readonly PerfInterval object that specifies rollup data collection every 5 minutes. You cannot retrieve 5-minute rollup data from an ESXi Server directly. You can use a vCenter Server connection to obtain 5-minute rollup data for an ESXi Server. The following table shows the historical interval property values on an ESXi server. You cannot modify this performance interval.
Name of the PerfInterval.
This PerfInterval is enabled on the system.
Statistics collection level. For an ESXi system, this property is null. The PerfInterval object on an ESXi system defines the baseline interval.
vCenter Server Performance Intervals
A vCenter Server system aggregates performance data from all ESXi systems that it manages. The amount of data aggregated depends on the level setting configured for the vCenter Server. The level settings are reflected in the PerformanceManager.historicalInterval property for the vCenter Server system. historicalInterval is an array of PerfInterval data objects that define four different level settings, 1 through 4.
Values of PerfInterval Data Objects from a vCenter Server System lists the default values for the performance intervals on a vCenter Server system.
By default, the collection level is set to 1 for each of the four intervals. Using the default level, a vCenter Server will collect data for all performance counters that specify collection level 1. Using the default length value, a vCenter Server will save collection data for the following time periods:
Data older than a year is purged from the vCenter Server database.