You can collect statistical data for all managed objects in your vCenter Server system. Statistical data consists of CPU, memory, disk, network, system, and virtual machine operations metrics.

Metric Groups lists each metric group and describes the type of data collected.

Metric Groups

Metric group



CPU utilization per host, virtual machine, resource pool, or compute resource.


Memory utilization per host, virtual machine, resource pool, or compute resource. The value obtained is one of the following:

For virtual machines, memory refers to guest physical memory. Guest physical memory is the amount of physical memory presented as a virtual-hardware component to the virtual machine, at creation time, and made available when the virtual machine is running.

For hosts, memory refers to machine memory. Machine memory is the random-access memory (RAM) that is installed in the hardware that comprises the ESX/ESXi system.


Disk utilization per host, virtual machine, or datastore. Disk metrics include input/output (I/O) performance (such as latency and read/write speeds), and utilization metrics for storage as a finite resource.


Network utilization for both physical and virtual network interface controllers (NICs) and other network devices, such as the virtual switches (vSwitch) that support connectivity among all components (hosts, virtual machines, VMkernel, and so on).


Overall system availability, such as system heartbeat and uptime. These counters are available directly from ESX and from vCenter Server.

Virtual Machine Operations

Virtual machine power and provisioning operations in a cluster or datacenter.

For a complete list of all statistics available for ESX/ESXi hosts and collected by vCenter Server, see the PerformanceManager API documentation pages in the vSphere API Reference.