To set up how statistical data is recorded, you configure collection intervals for statistics. You can access the stored statistical information through command-line monitoring utilities or by viewing performance charts in the vSphere Client.

Configure Statistics Collection Intervals in the vSphere Client

Statistic collection intervals determine the frequency at which statistic queries occur, the length of time statistical data is stored in the database, and the type of statistical data that is collected. You can view the collected statistics through the performance charts in the vSphere Client or through command-line monitoring utilities.

Note: Not all interval attributes are configurable.

Prerequisites

Required privilege: Performance.ModifyIntervals

Procedure

  1. In the vSphere Client, navigate to the vCenter Server instance.
  2. Select the Configure tab.
  3. Under Settings, select General.
  4. Click Edit.
  5. To enable or disable a statistics interval, check the box for that interval.
  6. To change a statistics interval attribute value, select a value from the drop-down menu.
    1. In Interval Duration, select the time interval in which statistics data is collected.
    2. In Save For, select for how long the archived statistics are kept in the database.
    3. In Statistics Level, select a new level for collecting statistics.
      The lower the level is, the fewer number of statistic counters are used. Level 4 uses all statistics counters. Use it only for debugging purposes.

      The statistics level must be less than or equal to the statistics level that is set for the preceding statistics interval. This requirement is a vCenter Server dependency.

  7. (Optional) In Database Size, estimate the effect of the statistics settings on the database.
    1. Enter the number of Physical Hosts.
    2. Enter the number of Virtual Machines.
      The estimated space required and number of database rows required are calculated and displayed.
    3. If necessary, make changes to your statistics collection settings.
  8. Click Save.

Example: Relationships Between the Default Settings for Statistics Intervals

  • Samples that are collected every 5 minutes are stored for 1 day.
  • Samples that are collected every 30 minutes are stored for 1 week.
  • Samples that are collected every 2 hours are stored for 1 month.
  • Samples that are collected on 1 day are stored for 1 year.

For all statistics intervals, the default level is 1. It uses the Cluster Services, CPU, Disk, Memory, Network, System, and Virtual Machine Operations counters.

Data Collection Levels

Each collection interval has a default collection level that determines the amount of data gathered and which counters are available for display in the charts. Collection levels are also referred to as statistics levels.

Table 1. Statistics Levels
Level Metrics Best Practice
Level 1
  • Cluster Services (VMware Distributed Resource Scheduler) – all metrics
  • CPU – cpuentitlement, totalmhz, usage (average), usagemhz
  • Disk – capacity, maxTotalLatency, provisioned, unshared, usage (average), used
  • Memory – consumed, mementitlement, overhead, swapinRate, swapoutRate, swapused, totalmb, usage (average), vmmemctl (balloon), totalbandwidth (DRAM or PMem)
  • Network – usage (average), IPv6
  • System – heartbeat, uptime
  • Virtual Machine Operations – numChangeDS, numChangeHost, numChangeHostDS

Use for long-term performance monitoring when device statistics are not required.

Level 1 is the default Collection Level for all Collection Intervals.

Level 2
  • Level 1 metrics
  • CPU – idle, reservedCapacity
  • Disk – All metrics, excluding numberRead and numberWrite.
  • Memory – All metrics, excluding memUsed, maximum and minimum rollup values, read or write latency (DRAM or PMem).
  • Virtual Machine Operations – All metrics
Use for long-term performance monitoring when device statistics are not required but you want to monitor more than the basic statistics.
Level 3
  • Level 1 and Level 2 metrics
  • Metrics for all counters, excluding minimum and maximum rollup values.
  • Device metrics

Use for short-term performance monitoring after encountering problems or when device statistics are required.

Level 4 All metrics supported by the vCenter Server, including minimum and maximum rollup values.

Use for short-term performance monitoring after encountering problems or when device statistics are required.

Note:

When the statistics levels, level 3 or level 4 are used beyond the default value, it may cause one particular process, vpxd, to sustain memory growth, if it cannot save the statistics information to the database as quickly as required. If the usage limit of these statistics levels is not monitored closely, it may cause vpxd to grow out of memory and eventually crash.

So, in case the administrator decides to elevate any of these levels, it is necessary for the administrator to monitor the size of the vpxd process to make sure that is not growing boundlessly after the change.