Checking the statistics of the vCenter server is crucial when troubleshooting and performance monitoring in the VMware environment. The recording of the statistical data can be controlled in the statistical collection intervals. The statistical collection data controls the frequency of the statistics, length of the time it keeps in the database, and the type of the data collected.
What Are The VMware vCenter Data Collection Levels
Each statistics collection interval is associated with a Data Collection Level, which determines the amount of data collected and the counters associated in the performance graphs. Three main factors contributing to the statistics intervals.
- Interval Duration – time interval for the statistics data
- Save For – How long the archived collected data keeps in the database
- Statistics Level – Number of statistical counters used to collect the data (varies from Level 1 to Level 4), when the number is higher the high number of counters are used to collect the data. Level 4 use all the counters available and recommend only for debugging purposes.
How To Change The vCenter Statistics Intervals
To change the default statistics levels, Select the vCenter Server in the inventory -> Configure -> General (under Settings). You can expand the Statistics to view the current configuration
To change the Interval Duration, Save For and Statistics Level parameters click on Edit… and click on the parameter value, drop down will appear here and you can also enable/disable the statistics collection
There is an optional feature, which you can estimate the size of the database according to the number of Physical Hosts, Number of Virtual Machines and the configured statistics levels. Below output shows the database size as 246.55 GB for 100 ESXi hosts, 2000 Virtual Machines with 5 minutes Interval Duration for 5 days with Level 4 statistics level.
Note: Changing the statistics parameters can negatively affect to the vCenter performance and you have pay extra attention when you are changing these parameters. Impact of the statistics collection depend on the Inventory size.
These are the default settings for the Statistics Collection Intervals:
- Collected data with Level 1 Statistics level in every 5 minutes are stored for 1 day
- Collected data with Level 1 Statistics level in every 30 minutes are stored for 1 week
- Collected data with Level 1 Statistics level in every 2 hours are stored for 1 month
- Collected data with Level 1 Statistics level in every 1 day are stored for 1 year
What Are The Differences In These Statistics Levels?
So, we know that there are four statistics levels and let’s see hat are the differences in these statistics levels.
|Statistics Collection Level||Used Metrices||Usaged Recommendation|
|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), IPv6
System – heartbeat, uptime
Virtual Machine Operations – numChangeDS, numChangeHost, numChangeHostDS
|Suitable for short term performance monitoring without device statistics and this is the default setting|
|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
|Suitable for long term performance monitoring with device statistics|
|3||Level 1 and Level 2 metrics
Metrics for all counters, excluding minimum and maximum rollup values.
|Use for short term performance monitoring with device statistics, probably monitor after an incident. Use only for day or a week performance monitoring, vCenter performance can be impacted and closely monitor the database space and usage in VAMI interface if VCSA|
|4||All metrics supported by the vCenter Server, including minimum and maximum rollup values.||Only for a very short period and closly monitoring must be required. Use only for after an incident.|
Article Short Link: https://tcrum.net/StatCollectionIntervals
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