Each data counter includes several attributes that are used to determine the statistical value collected. See the vSphere API Reference for a complete list and description of supported counters.

Table 1. Data Counter Attributes
Attribute Description
Unit of Measurement

Standard in which the statistic quantity is measured.

  • Kilobytes (KB) – 1024 bytes
    Note: Technically, 1 Kilobytes (KB) = 1000 bytes and 1 Kibibyte (KiB) = 1024 bytes. However, based on the context, kilobyte is also used for 1024 bytes in the computer science literature interchangeably.
  • Kilobytes per second (KBps) – 1024 bytes per second
  • Kilobits (kb) – 1000 bits
  • Kilobits per second (kbps) – 1000 bits per second
  • Megabytes (MB)
  • Megabytes per second (MBps)
  • Megabits (Mb), megabits per second (Mbps)
  • Megahertz (MHz)
  • Microseconds (µs)
  • Milliseconds (ms)
  • Number (#)
  • Percent (%)
  • Seconds (s)
  • Watts (watt)
  • Joules (joule)
  • Terabytes (teraBytes)
  • Temperature in celsius (celsius)
Description Text description of the data counter.
Statistics Type

Measurement used during the statistics interval. Related to the unit of measurement.

  • Rate – Value over the current statistics interval. For example:

    CPU Usage: Amount of CPU actively used by the host, resource pool, or virtual machine in the cluster.

    Counter: usagemhz

    Stats Type: Rate

    Unit: MegaHertz (MHz)

  • Delta – Change from previous statistics interval. For example:
    CPU System Time for vCPU (%): Amount of time spent on system processes on each virtual CPU in the virtual machine.
    Note: This is the host view of the CPU usage, not the guest operating system view.

    Counter: system

    Stats Type: Delta

    Unit: Percentage (%)

  • Absolute – Absolute value (independent of the statistics interval). For example:

    Memory: Amount of host machine memory used by all powered on virtual machines in the cluster. A cluster's consumed memory consists of virtual machine consumed memory and overhead memory. It does not include host-specific overhead memory, such as memory used by the service console or VMkernel.

    Counter: consumed

    Stats Type: Absolute

    Unit: MegaBytes (MB)
Rollup Type

Calculation method used during the statistics interval to aggregate data. Determines the type of statistical values that are returned for the counter.

  • Average – Data collected during the interval is aggregated and averaged. For example:

    Virtual Disk Read Requests: Number of virtual disk read commands completed on each virtual disk on the virtual machine. The aggregate number of all virtual disk read commands is also displayed in the chart.

    Counter: numberRead

    Stats Type: Absolute

    Unit: Number

    Rollup Type: Average

  • Minimum – The minimum value is rolled up.
  • Maximum – The maximum value is rolled up.

    The Minimum and Maximum values are collected and displayed only in statistics level 4. Minimum and maximum rollup types are used to capture peaks in data during the interval. For real-time data, the value is the current minimum or current maximum. For historical data, the value is the maximum or minimum of the aggregated values.

    For example, the following information for the CPU usage chart shows that the average is collected at statistics level 1. The minimum and maximum values are collected at statistics level 4.
    • Counter: usage
    • Unit: Percentage (%)
    • Rollup Type: Average (Minimum/Maximum)
    • Collection Level: 1 (4)
  • Summation – Data collected is summed. The measurement displayed in the chart represents the sum of data collected during the interval. For example:

    Network Packets Received: Number of network packets received across the top ten physical NIC instances on the host. The chart also displays the aggregated value for all NICs.

    Counter: packetRx

    Stats Type: Absolute

    Unit: Number

    Rollup Type: Summation

  • Latest – Data collected during the interval is a set value. The value displayed in the performance charts represents the current value. For example:

    Space in GB (Allocated): Total amount of logical datastore space provisioned by an administrator for the virtual machine. It is the storage size up to which the virtual machine files on datastores can grow. This includes log files, VMX files, and other miscellaneous files. Allocated space is not always in use.

    Counter: provisioned

    Stats Type: Absolute

    Unit: Gigabytes (GB)

    Rollup Type: Latest
Collection level A collection level determines the number of data counters used to collect statistics data. Collection levels are also referred as statistics levels. These collection levels vary from 1 to 4, with Level 4 having the most counters.
  • Level 1 is the least detailed statistics level and only includes the most critical statistics, such as aggregate CPU, memory, and network usage.
  • Level 2 introduces a number of additional statistics
  • Level 3 incorporates per instance statistics, for example CPU usage of a host on a per-CPU basis.
  • Level 4 is the most detailed and is inclusive of all the other levels

For more information on collection levels, see Data Collection Levels.

Note: Be careful when you set a higher collection level, as the process requires significant increase of resource usage.