Reconnect ESXi host after reinstall

After a VMware ESXi host reinstall reconnecting your host is not as easy as changing the state of the host by using the Set-VMHost -State command in VMware PowerCLI. The reason is that your host has gotten a new certificate. So to do this scripted you need to retrieve the SSL thumbprint and specify that during the reconnect.

Continue reading Reconnect ESXi host after reinstall

Enable IPv6 using PowerCLI

This is a PowerCLI script to enable IPv6 on VMware ESXi hosts in you vCenter.

This problem is that disabling IPv6 in newer versions of ESXi can sometimes result in PSOD, so even if you are not using IPv6 in your environment, you should keep it enabled. https://kb.vmware.com/s/article/2150794

Import-Module VMware.PowerCLI

Connect-VIServer <Insert vCenter name>

$VMHost = Get-VMHost <insert hostname>

$esxcli = Get-EsxCli -VMHost $VMhost -V2
$argument = $esxcli.system.module.parameters.set.CreateArgs()
$argument.module = "tcpip4"
$argument.parameterstring = "ipv6=1"
$esxcli.system.module.parameters.set.Invoke($argument)
Write-Host "IPv6 Enabled for host: $($VMHost)"
Write-Host "You need to put the host in maintenance mode and reboot for changes to take effect."

Hope this helps you. Keep in mind that use of this script is entirely your responsibility, and you should always understand what a script does before you run it.

To detect which host that has IPv6 disabled check this post: https://vm.knutsson.it/?p=1193

Check if IPv6 is disabled

This is a PowerCLI script to list VMware ESXi host that has IPv6 disabled in you vCenter.

This problem is that disabling IPv6 in newer versions of ESXi can sometimes result in PSOD, so even if you are not using IPv6 in your environment, you should keep it enabled. https://kb.vmware.com/s/article/2150794

Import-Module VMware.PowerCLI

Connect-VIServer <Insert vCenter server FQDN>
$VMHosts = Get-VMHost | Sort-Object

foreach ($VMHost in $VMHosts) {
    if ($VMHost.ConnectionState -ne "Connected" ) { 
        $status = "Unknown. Host Status: $($VMHost.Connectionstate)"
        Write-host("$($VMHost): $($status)")
    } else {
        $value = ($VMHost | Get-VMHostModule tcpip4).Options
        if ($value -match "ipv6=1") {
            $status = "Enabled"
            #Write-host("$($VMHost): $($status)")
        } elseif ($value -match "ipv6=0") {
            $status = 'Disabled'
            Write-host("$($VMHost): $($status)")
        } else {
            $status = "Unknown"
            Write-host("$($VMHost): $($status) - $($value)")
        }
    }
}

Hope this helps you. Keep in mind that use of this script is entirely your responsibility, and you should always understand what a script does before you run it.

To enable IPv6 on hosts using PowerCLI check this post: https://vm.knutsson.it/?p=1198

PowerCLI: Get ESXi Hosts Version and Uptime

This is a quick and easy script to get all hosts from a vCenter sorted by Cluster and Host name. You will get the Cluster, Hostname, Version, Build and Uptime in days.

Connect-VIServer <vCenter FQDN>


$clusters = Get-Cluster | Sort-Object
$objects = @()

foreach ($cluster in $clusters) {
    Write-Host "Gathering from cluster: $($cluster.Name)"

    $vmhosts = $cluster | Get-VMHost | Sort-Object
    
    foreach ($vmhost in $vmhosts) {
        $object = New-Object -TypeName PSObject
        $object | Add-Member -MemberType NoteProperty -Name "Cluster" -Value $cluster
        $object | Add-Member -MemberType NoteProperty -Name "Host" -Value $vmhost
        $object | Add-Member -MemberType NoteProperty -Name "Version" -Value $vmhost.Version
        $object | Add-Member -MemberType NoteProperty -Name "Build" -Value $vmhost.Build
        $object | Add-Member -MemberType NoteProperty -Name "Uptime (Days)" -Value (New-TimeSpan -Start $vmhost.ExtensionData.Summary.Runtime.BootTime -End (Get-Date) | Select-Object -ExpandProperty Days)
        $objects += $object
    }
}

$objects | ft -AutoSize

Powershell: Find largest VM disk

Sometimes you need to find the largest virtual disk. Lets say if you are sizing LUNs for datastores.

Here is a script that help you do that.

Requirement are powershell and the VMware.PowerCLI module.

Use it at your own risk.

Import-Module VMware.PowerCLI

Connect-VIServer <vCenter Name>


Function Get-LargestDisk {
  param(
    $Datastores=$null
  )
  $largest = 0

  if ($Datastores -eq $null) {
    Write-Host "Searching through all VMs."
    $vms = Get-VM
  } else {
    Write-Host "Searching through VMs on datastores: $Datastores"
    $vms = $Datastores | Get-VM
  }

  foreach ($vm in $vms) {
    $hdds = $vm | Get-HardDisk

    foreach ($hdd in $hdds) {
      $size = $hdd.CapacityGB

      if ($size -gt $largest) {
        Write-Host "Found a larger VM: $vm Size: $size GB"
        $largestVm = $vm
        $largest = [math]::Round($size)
      }
    }
  }
  Write-Host "Largest Disk: $largest GB Largest VM: $largestVm"
}

Get-LargestDisk -Datastore (Get-Datastore V7000*)

Cross SSO and vCenter VMotion using PowerCLI

http://cloudmaniac.net/using-powercli-to-vmotion-vm-between-different-sso-domains-vcenters/

Roman Decker wrote an article about how to move virtual machine between vCenters that are not part of the same SSO domain, using PowerCLI.

I felt like it needed some adjustments to be more dynamic and interactive, so many of the hard coded bits I decided to make the script ask for at runtime.

Continue reading Cross SSO and vCenter VMotion using PowerCLI