Each collection interval has a default statistics level that determines how many data counters are used when you collect statistics data.

The statistics level establishes which metrics are retrieved and recorded in the vCenter Server database. You can assign a statistics level of 1- 4 to each collection interval, with level 4 having the largest number of counters. By default, all collection intervals use statistics level 1.

The statistics level for an interval cannot be greater than the statistics level set for the preceding collection interval. For example, if the Month interval is set to statistics level 3, the Year interval can be set to statistics level 1, 2, or 3, but not to statistics level 4. This is a vCenter Server dependency.

Statistics Levels describes each statistics level and provides recommendations on when to use them.

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)

Network – usage (average)

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 and maximum and minimum rollup values.

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.

Because of the large quantity of troubleshooting data retrieved and recorded, use level 3 for the shortest time period ( Day or Week collection interval).

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.

Because of the large quantity of troubleshooting data retrieved and recorded, use level 4 for the shortest amount of time.

Generally, you use only statistics levels 1 and 2 for performance monitoring and analysis. Levels 3 and 4 provide granularity that is useful only for developers. Unless vCenter Server is set to a statistics level that contains a data counter, the data for that counter is not stored in the database nor is it rolled up into a past-day statistic on the ESX/ESXi host. The counter will not appear in the performance charts.