Specifications

Chapter 3: Administration and setup
Virtualization Manager also calculates peak sample values. Peak values are the
maximum values from the 20 second samples. For example, if the default 10
minute data collection interval is used, the peak value is the maximum value from
the 30 values received in the previous 10 minutes. The sample values collected
every 20 seconds are not stored in Virtualization Manager, because they
represent a big amount of data. These values are used to compute the average or
maximum value from out of the raw values.
Sample collection in a Hyper-V environment
Virtualization Manager collects two sets of samples for hosts, clusters, and data
stores, with one minute delay between the two sample sets. The average values
are calculated from the difference between the two sample sets, and from the time
that elapsed between them.
For VMs, the current values are collected, that is, the values that are available at
the moment of the request.
As opposed to VMware, there are no peak values calculated for a Hyper-V
environment.
Data rollup
Raw performance data is rolled up over time, to provide hourly, daily, weekly,
monthly and quarterly averages, maximal, and other statistics. The rollup periods
are based on the local server time and do not take business hours into account.
The raw and hourly performance data consumes large amounts of storage
capacity, and it is discarded after a configurable amount of time. Higher level
rollups are retained indefinitely for record keeping purposes, cost accounting, and
to act as a data warehouse. This information provides administrators with long
term trends in resource consumption.
Peak values are calculated in the following way:
l Latest Value (peak): The highest values of each sample collected from
VMware. VMware collects raw data in 20 second intervals.
100