Lab Automation with PowerCLI Part 2: Gathering Performance Statistics

December 9th at 12:00am

Ever wondered how to programatically gather performance statistics from an ESXi server? This article aims to explain:

- How to find a list of statistics that are available for gathering
- How to gather the stats to a file for analysis

 

Previous Article: Getting started

Next Article: Create and Delete Virtual Machines

Notes:

To get started, you can find out what statistics are available by running this script:

Add-PSSnapin "Vmware.VimAutomation.Core"

#Connect to ESXi host, Gather stats & disconnect
Connect-VIServer -Server 10.10.10.100 -User root -Password S0mePsswrd$
Get-VMHost | Get-StatType
Disconnect-VIServer -Server 10.10.10.100 -Force


Note: If you get an error message, comment out the "Add-PSSnapin" line. It only needs to be run once every time you open Powershell ISE

This script generates a Really Long List. For convenience, you can download the complete list here (adfly ad)

Gathering Disk Read/Write statistics

Ok now that you have a HUGE list of statistics, which ones would you want to gather? We find disk statistics helpful, as that is oftentimes the bottleneck in our environment. The following script can be used to gather disk read & write statistics from a single host. With a little creativity, it could be genericized (new word. :) ) and put in a loop to gather constantly:

#Add-PSSnapin "Vmware.VimAutomation.Core"

#Define Statistics gathering directories
$DiskRepath = "c:\diskreadstats.txt"
$DiskWrPath = "c:\diskwritestats.txt"

#Connect to ESXi host, Gather stats & disconnect
$ESXIHost = "10.10.10.100"
Connect-VIServer -Server $ESXIHost -User root -Password Admin!!

Write-Host "Gathering Disk Read Statistics"
Get-Stat -Entity $ESXIHost -Stat disk.read.average | Out-File -FilePath $DiskRePath -Append

Write-Host "Gathering Disk Write Statistics"
Get-Stat -Entity $ESXIHost -Stat disk.write.average | Out-File -FilePath $DiskWrPath -Append
   
Disconnect-VIServer -Server $ESXIHost -Force

 

The output looks something like this:

MetricId                Timestamp                          Value Unit
--------                ---------                          ----- ----
disk.read.average       12/9/2011 10:00:40 PM                  0 KBps
disk.read.average       12/9/2011 10:00:20 PM                340 KBps

 

With Powershell & PowerCLI you can keep a handle on the performance in your virtualized environment. Gathering statistics / counters in an automated way can help you better diagnose & resolve bottlenecks.

Download the scripts from Today's article: Sample Scripts (adfly)

Previous Article: Getting started

Next Article: Create and Delete Virtual Machines