Performance metrics are collected on ESX/ESXi servers and vCenter Servers for managed objects and the physical and virtual devices associated with these objects. Each object and device has its own set of data counters that provide the metadata for the metrics.

The performance metrics for VMware vSphere are organized into tables for each metric group: cluster services, CPU, disk, management agent, memory, network, system, and virtual machine operations. Each table contains the following information:


Lists the display name of each data counter.


Indicates the name of the data counter as displayed in the APIs and advanced performance charts. In some cases the labels are different in the overview performance charts.


Provides a brief description of the metric.

Stats Type

Measurement used during the statistics interval. The Stats Type is related to the unit of measurement and can be one of the following:

Rate - Value over the current statistics interval.

Delta - Change from previous statistics interval.

Absolute - Absolute value, independent of the statistics interval .


How the statistic quantity is measured across the collection interval, for example, kiloBytes (KB) and kiloBytesPerSecond (KBps).


For some statistics, the value is converted before it is displayed in the overview performance charts. For example, memory usage is displayed in KiloBytes by the APIs and the advanced performance charts, but it is displayed in MegaBytes in the overview performance charts.

Rollup Type

Indicates the calculation method used during the statistics interval to roll up data. Determines the type of statistical values that are returned for the counter. For real-time data, the value shown is the current value. One of:

Average - Data collected is averaged.

Minimum - The minimum value collected is rolled up.

Maximum - The maximum value collected is rolled up.

Summation - Data collected is summed.

Latest - Data collected is the most recent value.

Collection Level

Indicates the minimum value to which the statistics collection level must be set for the metric to be gathered during each collection interval. You can assign a collection level of 1 to 4 to each collection interval enabled on your vCenter Server, with 4 containing the most data counters.


Indicates the entity for which the counter applies. One of:

V – virtual machines

H – hosts

R – resource pools

C – compute resources

D – datastores

Calculations for all metrics listed in the data counter tables are for the duration of the data collection cycle. Collection cycle durations are specified with the Statistics Collection Interval setting.


The availability of some data counters in the vSphere Client depends on the statistics Collection Level set for the vCenter Server. The entire set of data counters are collected and available in vCenter Server. You can use the vShpere Web Services SDK to query vCenter Server and get statistics for all counters. For more information, see the VMware vSphere API Reference.