Jere's Techblog

Compare ActiveDirectory ACL

Here are some examples and a good description of the ActiveDirectory ACL:

Script example to compare ActiveDirectory OU ACL ( Security Groups )

by J.Kühnis 25.11.2019

Import-Module ActiveDirectory

$OU1 = Get-ACl -Path 'AD:\OU=Sales,OU=UserAccounts,DC=FABRIKAM,DC=COM' |  Select-Object -ExpandProperty Access | select IdentityReference

$OU2 = Get-ACl -Path 'AD:\OU=Marketing,OU=UserAccounts,DC=FABRIKAM,DC=COM' |  Select-Object -ExpandProperty Access | select IdentityReference

Compare-Object $OU1 $OU2 -IncludeEqual
Continue reading...

Function Count Ad-GroupMember

#by J.Kühnis 12.11.2019
Function Count-ADGroupMember {
        [Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true)]

    #Get Data From AD-Group
    $groupdsn = (Get-ADGroup $groupname).DistinguishedName
    $group = [adsi]"LDAP://$groupdsn" 
    $groupmemebrs = $group.psbase.invoke("Members") | ForEach-Object { $_.GetType().InvokeMember("SamAccountName", 'GetProperty', $null, $_, $null) }
    $ADGroupMemberCount = $groupmemebrs.count
    return $ADGroupMemberCount


Count-ADGroupMember -GroupName AnyGroupNameHere
Continue reading...

PowerCLI: Create VM Engine

Here is an example of how to make automated VM’s with PowerCLI. You can customize the vLAN, DiskType, etc.

If you reuse the Script below, I would recommend to look at the parameters and adapt them to your environment, e.g. network/storage config like the vLan,ESXI Hosts or the adapter type you are using its VMWare.


Create-CustomVirtualMachine -Hostname 'MyServer' -NumCPU 6 -DiskSize 80 -RAMinGB 12 -OS Srv2016

Ensure you are using this script with PowerCLI or with the PowerCLI Module / Assemblys.

The script can also be saved and imported as a module (.psm1).

Import-Module "Path:\to\your\module\share\Create-VM_onFreeDatastore.psm1" -Verbose

Script to create VMs on Hypervisor with enough free ressources

#by J.Kühnis 06.11.2019
    $VmHostArray = @()

    Class VMHost {

Function Get-VMHostVirtualMachineVMs {
        [Parameter(Mandatory = $true)][String] $VMhost,
    IF ($ExtendedProperties -eq $true) {
        IF ($global:VMhostsVM = (Get-VMHost -Name $VMhost | Get-VM | select MemoryGB, VMHost, Name)) {
            return $global:VMhostsVM
    Else {
        IF ($global:VMhostsVM = ((Get-VMHost -Name $VMhost | Get-VM).Name | sort)) {
            return $global:VMhostsVM
    return $false
Function Get-vmHostDataStore {
        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
    $global:DatastoreID = (get-datastore -Id $DatastoreIDList)           
    return  $global:DatastoreID
Function Create-VMEngine {
        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]

    write-host "Hypervisor Parameters:" $VMName $EsxiHost $Datastore $MemoryGB $Vlan
    write-host (get-date -f HH:mm:ss)"Start VM Creation $VmName, please wait..."
    If (Get-VM *$VMName*) {
        Write-Host "VM $VMName already exists!!!, Skip this Hostname." -ForegroundColor RED -BackgroundColor Black

    IF ($OS -eq 'Win10') {
        New-VM -Name $VmName -ResourcePool $EsxiHost -Datastore $Datastore -NumCPU $NumCPUCore -MemoryGB $MemoryGB -NetworkName $Vlan -GuestID windows9_64Guest -DiskGB $DiskSize -DiskStorageFormat $HDFormat
    Else {
        New-VM -Name $VmName -ResourcePool $EsxiHost -Datastore $Datastore -NumCPU $NumCPUCore -MemoryGB $MemoryGB -NetworkName $Vlan -GuestID windows9Server64Guest -DiskGB $DiskSize -DiskStorageFormat $HDFormat

    # Set SCSI Controller
    Get-ScsiController -VM $VmName | Set-ScsiController -Type VirtualLsiLogicSAS >$NULL -WarningAction SilentlyContinue
    Write-host "Configure VM $VMName"
    # Configure vCPU & Core
    $VmName = Get-VM -name $VmName
    set-vm -vm $VmName -numcpu $TotalCpu -Confirm:$false >$NULL

    # Configure MAC-Address and Adapter Type
    $vm = Get-VM -Name $vmName
    $nic = Get-NetworkAdapter -VM $vm
    $global:spec = New-Object VMware.Vim.VirtualMachineConfigSpec
    $devSpec = New-Object VMware.Vim.VirtualDeviceConfigSpec
    $devSpec.Device = $nic.ExtensionData
    $devSpec.operation = "edit"
    $spec.DeviceChange += $devSpec
    Set-NetworkAdapter -NetworkAdapter $nic -Type Vmxnet3 -Confirm:$false >$NULL

    $spec = New-Object VMware.Vim.VirtualMachineConfigSpec
    $spec.Firmware = [VMware.Vim.GuestOsDescriptorFirmwareType]::bios
    try {
    catch {

    #special Parameters
    New-AdvancedSetting -Entity $vm -Name ethernet0.pciSlotNumber -Value 192 -Confirm:$false -Force:$true >$NULL -WarningAction SilentlyContinue
    Write-host "VM Config finished"
    write-host (get-date -f HH:mm:ss)"VM Creation $VmName finished!" -ForegroundColor "Green"


Function Create-CustomVirtualMachine {
        [Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true)][string]$Hostname,
        [Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true)][ValidateRange(1, 16)][int]$NumCPU,
        [Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true)][ValidateRange(1, 250)][int]$DiskSize,
        [Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true)][ValidateRange(1, 32)][int]$RAMinGB,
        [Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true)][ValidateSet('Win10', 'Srv2016')][string]$OS

    Write-host "------------------------"`n"| Start VmWare Section |"`n"------------------------"  -ForegroundColor WHITE
    (get-vmhost, | select Name, State, Parent, DatastoreIdList, MemoryTotalGB, MemoryUsageGB) | % {
        #$FreetoUseMemory = ("{0:N0}" -f $_.MemoryTotalGB) - ("{0:N0}" -f $_.MemoryUsageGB)
        $myhost = New-Object VMhost -Property @{Name = $_.Name; State = $_.State; Parent = $_.Parent; DatastoreIdList = $_.DatastoreIdList; MemoryTotalGB = $_.MemoryTotalGB; MemoryUsageGB = $_.MemoryUsageGB; }
        $VmHostArray += $myhost
    Foreach ($VmWareHost in $VmHostArray) {
        $VmWareHost.ReservedVMmemory = ((Get-VMHostVirtualMachineVMs $VmWareHost.Name -ExtendedProperties $true).MemoryGB | Measure-Object -sum).sum
        $VmWareHost.FreetoUseMemory = ("{0:N0}" -f $VmWareHost.MemoryTotalGB) - ("{0:N0}" -f $VmWareHost.ReservedVMmemory);

    $VmHostArray = $VmHostArray | Sort-Object -Property FreetoUseMemory -Descending

    #Check RAM Space on ESXI Host with 10GB reserves on Host
    IF (($VmHostArray[0].FreetoUseMemory - 10) -ge ($RAM)) {
        #Check if Disk has 10GB Free Storage
        IF (get-vmHostDataStore -DatastoreIDList $VmHostArray[0].DatastoreIdList) {
            $specVMDatastore = (get-vmHostDataStore -DatastoreIDList $VmHostArray[0].DatastoreIdList | Sort-Object -Property FreeSpaceGB -Descending)
            [int]$a = ("{0:N0}" -f $specVMDatastore[0].FreeSpaceGB).Replace("'", "")
            IF ($a -ge ($DiskSize + 10) ) {
                $specVMDatastore = $specVMDatastore[0].Name
                $VMName = $Hostname
                $EsxiHost = $VmHostArray[0].Name
                $Datastore = $specVMDatastore
                [int]$NumCPUCore = 1
                $Vlan = 'Some_VlanName'
                $HDFormat = "Thin"
                [int]$TotalCPU = $NumCPU

                # Create VM on Host
                Create-VMEngine -VMName $VMName -EsxiHost $EsxiHost -Datastore $Datastore -MemoryGB $RAMinGB -Vlan $Vlan -NumCPUCore $NumCPUCore -HDFormat $HDFormat -TotalCPU $TotalCPU -DiskSize $DiskSize -OS $OS
                Write-host "----------------------"`n"| End VmWare Section |"`n"----------------------"  -ForegroundColor WHITE
            Else {
                Write-host $Hostname "| not enough storage on ESXI Host! Action stopped." -ForegroundColor Yellow -BackgroundColor Black
        Else {
            Write-host $Hostname "| No Datastore found. Action stopped" -ForegroundColor Yellow -BackgroundColor Black
    Else {
        Write-Host $Hostname "| not enough on ESXI Host. Action stopped" -ForegroundColor Yellow -BackgroundColor Black

Continue reading...

Jobs on PowerShell

Certain processes can take a long time. As an example, if you want to search a specific event log trough several servers.
To counteract this, Powershell has introduced “Jobs, Workflows and Foreach-Parallel”. It should be well estimated what you can use where best. Personally, I like to rely on jobs when it comes to remote querying / remote invocation.

There is a sensational blogpost by Harry Eagles bout the topic:

I would like to show a small example of how I use Jobs to read out Eventlogs about several machines. In the example, it is only checked if the corresponding log exists or was written in the last 45 minutes. For 128 servers I needed 30 minutes with this parallel Task. I killed the sequential script after 6 hours …

#by J.Kühnis
$Servers = @(

Remove-Job *
$outputArray = @()

Foreach ($Server in $Servers){

Start-Job -Name $Server -ArgumentList $Server{
    IF(Get-EventLog -LogName System -InstanceId '12306' -After (Get-Date).AddMinutes(-45) -ComputerName $servername -ErrorAction Ignore){
    Write-Output"$servername  true"
    Write-Output "$servername  false"


While (Get-Job -State "Running") {
    write-host "Jobs Running"  (Get-Job).count
    Start-Sleep 2
write-host "Jobs completed, getting output"

Get-Job | ForEach-Object {
    $a = Receive-Job $_.Id
    $outputArray += $a

#Use the variable $outputArray to get or export the Outputdata
Continue reading...