Powershell GatherIOPS

################################################################################
# GatherIOPS v1.2
# by Curtis Salinas
# http://virtualcurtis.wordpress.com
# October 2010
################################################################################
#
# Given an array of datastore names, a vCenter Server FQDN,
# and a number of samples, this script will return a table
# of the read and write IOPS done by every virtual machine
# on those datastores over the sample interval. This data
# is output to the PowerShell screen and to a csv file
# called "IOPSReport.csv".
#
# Example:
# GatherIOPS.ps1 -server myvcenterserver.mydns.com -datastores @("DS01") -numsamples 90
#
# Returns:
# VM     Interval (minutes)         Avg Write IOPS            Avg Read IOPS
# --     ------------------         --------------            -------------
# VM01                   30       9.97194444444444            0.466111111111111
# VM01                   30       3.03222222222222            0.483888888888889
# VM01                   30                 8.7625            0.104444444444444
# VM01                   30       6.73638888888889            0.211111111111111
# VM01                   30       15.5652777777778            0.303055555555556
#
################################################################################


param($datastores, $server, $numsamples)

$datastores = "server1", "server2", "server3"
$Server = "vCenter"
$numsamples = 90

# $username = read-host -prompt "Please enter local user account for host access"
# read-host -prompt "Please enter password for host account" -assecurestring | convertfrom-securestring | out-file cred.txt
# $password = get-content cred.txt | convertto-securestring
# $credentials = new-object -typename System.Management.Automation.PSCredential -argumentlist $username,$password
$username = "root"
$password = get-content c:\users\MyUser\desktop\iops\cred.txt | convertto-securestring
$credentials = new-object system.management.automation.pscredential $username, $password

# add VMware PS snapin
if (-not (Get-PSSnapin VMware.VimAutomation.Core -ErrorAction SilentlyContinue)) {
    Add-PSSnapin VMware.VimAutomation.Core
}

# connect vCenter server session
Connect-VIServer $server -NotDefault -WarningAction SilentlyContinue | Out-Null


# function to get average iops for a vm on a particular host
function GetAvgStat($vmhost,$vm,$ds,$samples,$stat){
    # number of samples = x time
    # 180 = 60min
    # 90 = 30min
    # 45 = 15min
    # 15 = 5min
    # 3 = 1min
    # 1 = 20sec (.33 min)

    # connect to host
    connect-viserver -server $vmhost -credential $credentials -NotDefault -WarningAction SilentlyContinue | Out-Null

    # identify device id for datastore
    $myDatastoreID = ((Get-Datastore $ds -server $vmhost) | Get-View).info.vmfs.extent[0].diskname

    # gather iops generated by vm
    $rawVMStats = get-stat -entity  (get-vm $vm -server $vmhost) -stat $stat -maxSamples $samples
    $results = @()

    foreach ($stat in $rawVMStats) {
        if ($stat.instance.Equals($myDatastoreID)) {
            $results += $stat.Value
        }
    }

    $totalIOPS = 0
    foreach ($res in $results) {
        $totalIOPS += $res
    }

    return [int] ($totalIOPS/$samples/20)
}

$IOPSReport = @()

foreach ($datastore in $datastores) {

  # Grab datastore and find VMs on that datastore
  $myDatastore = Get-Datastore -Name $datastore -server $server
  $myVMs = Get-VM -Datastore $myDatastore -server $server | Where {$_.PowerState -eq "PoweredOn"}

  # Gather current IO snapshot for each VM
  $dataArray = @()
  foreach ($vm in $myVMs) {
  $data = "" | Select "VM", "Time", "Datastore", "Interval (minutes)", "Avg Write IOPS", "Avg Read IOPS"
  $data."VM" = $vm.name
  $data."Time" = Get-Date
  $data."Datastore" = $myDatastore.name
  $data."Interval (minutes)" = ($numsamples*20)/60
  $data."Avg Write IOPS" = GetAvgStat -vmhost $vm.host.name -vm $vm.name -ds $datastore -samples $numsamples -stat disk.numberWrite.summation
  $data."Avg Read IOPS" = GetAvgStat -vmhost $vm.host.name -vm $vm.name -ds $datastore -samples $numsamples -stat disk.numberRead.summation
  $dataArray += $data
  }

  # Do something with the array of data
  $IOPSReport += $dataArray

}

# set variable datetime to use for filename

$datetime = get-date -uformat "%m%d%Y-%H.%M"

# set variable IOPFilename that will combine date/time stamp to filename

#$IOPFilename = "IOPSReport"+$datetime+".csv"
#$IOPFilename = "IOPSReport.csv"

$IOPSReport
#$IOPSReport | Export-CSV -append $IOPFilename -NoType
$IOPSReport | Export-CSV "c:\users\MyUser\desktop\iops\IOPSReport.csv" -NoType