A client needed to remove the e1000 NIC from all VMs in a PVS pool and replace it with the VMXNET3 adapter. PVS VMs are registered by MAC address – replacing the NIC means a new MAC, and PVS has to be updated to allow the VM to boot.

I needed a script to remove the old e1000 NIC, add a new VMXNET3 NIC, and register the new NIC’s MAC with PVS. I knew I would easily accomplish the VM changes with PowerCLI, but I didn’t know what options there were with Citrix. I found what I needed in MCLIPSSNapin, a PowerShell snap-in installed on all PVS servers. The snap-in gives you Powershell control over just about anything you need to do on a PVS server.

I didn’t want to install PowerCLI on the production PVS servers, and I didn’t want to install PVS somewhere else or try manually copying files over. I decided I needed one script to swap out the NICs and dump a list of VMs and MAC address to a text file. Then a second script to read the text file and make the PVS changes.

First, the PowerCLI script. We put the desktop pool into maintenance mode with all desktops shut down. It takes about 10 seconds per VM to execute this script.

Param(
	[switch] $WhatIf
,
	[switch] $IgnoreErrors
,
	[ValidateSet("e1000","vmxnet3")]
	[string] 
 	$NICToReplace = "e1000"
)

# vCenter folder containing the VMs to update
$FOLDER_NAME = "YourFolder"

# vCenter Name
$VCENTER_NAME = "YourvCenter"

#The portgroup that the replacement NIC will be connected to
$VLAN_NAME = "VLAN10"

#If you want all VMs in $FOLDER_NAME, leave $VMFilter empty. Otherwise, set it to a pipe-delimited list of VM names
$VMFilter = ""
#$VMFilter = "DESKTOP001|DESKTOP002"

$LOG_FILE_NAME = "debug.log"

Connect-VIServer $VCENTER_NAME

$NICToSet = "e1000"

if ( $NICToReplace -eq "e1000" )
{
	$NICToSet = "vmxnet3"
}
elseif ( $NICToReplace -eq "vmxnet3" )
{
	$NICTOSet = "e1000"
}


function LogThis
{
	Param([string] $LogText,
      	[string] $color = "Gray")
 Process
 {
    write-host -ForegroundColor $color $LogText 
    Add-Content -Path $LOG_FILE_NAME $LogText
 }
}

if ( Test-Path $LOG_FILE_NAME )
{
    Remove-Item $LOG_FILE_NAME
}

$errStatus = $false
$warnStatus = $false
$msg = ""

if ( $VMFilter.Length -eq 0 )
{
	$vms = Get-Folder $FOLDER_NAME | Get-VM
}
else
{
	$vms = Get-Folder $FOLDER_NAME | Get-VM | Where{ $_.Name -match $VMFilter }
}

foreach ($vm in $vms)
{
	$vm.Name
	$msg = ""


	if ( $vm.NetworkAdapters[0] -eq $null )
	{
		$errStatus = $true
		$msg = "No NIC found on " + $vm.Name
		LogThis $msg "Red"

	}
	else
	{
		if ( ($vm.NetworkAdapters | Measure-Object).Count  -gt 1)		{
			$errStatus = $true
			msg = "Multiple NICs found on " + $vm.Name
			LogThis $msg "Red"

		}
		else
		{
			if ( $vm.NetworkAdapters[0].type -ne $NICToReplace )
			{
				$warnStatus = $true
				$msg = "NIC is not " + $NICToReplace + ", found" + $vm.NetworkAdapters[0].type + " on " + $vm.Name
				LogThis $msg "Yellow"				
			}

				LogThis $vm.Name,$vm.NetworkAdapters[0].MacAddress

		}

	}



}

if ( $errStatus = $true -and $IgnoreErrors -ne $true)
{
	LogThis "Errors found, please correct and rerun the script." "Red"
 
}
else
{
	if ( $warnStatus = $true )
	{
		LogThis "Warnings were found, continuing." "Yellow"
	}
	foreach ( $vm in $vms )
	{
		if ( $WhatIf -eq $true )
		{
			$msg = "Whatif switch enabled, would have added " + $NICToSet + " NIC to " + $vm.Name
			LogThis $msg
		}
		else
		{
			$vm.NetworkAdapters[0] | Remove-NetworkAdapter -confirm:$false
			$vm | New-NetworkAdapter -NetworkName $VLAN_NAME -StartConnected -Type $NICToSet -confirm:$false
		}
	}

	if ( $VMFilter.Length -eq 0 )
	{
		$vms = Get-Folder $FOLDER_NAME | Get-VM
	}
	else
	{
		$vms = Get-Folder $FOLDER_NAME | Get-VM | Where{ $_.Name -match $VMFilter }
	}

	LogThis("Replaced MAC addresses:")
	foreach ( $vm in $vms )
	{
		LogThis $vm.Name,$vm.NetworkAdapters[0].MacAddress
	}
	
	
}

The script offers a -Whatif switch so you can run it in test mode without actually replacing the NIC. It writes all its output to $LOG_FILE_NAME. First it logs the VMs with their old MAC, then the replaced MAC. The output looks something like this:
VD0001 00:50:56:90:00:0a
VD0002 00:50:56:90:00:0b
VD0003 00:50:56:90:00:0c
VD0004 00:50:56:b8:00:0d
VD0005 00:50:56:b8:00:0e
Replaced MAC addresses:
VD0001 00:50:56:90:57:1b
VD0002 00:50:56:90:57:1c
VD0003 00:50:56:90:57:1d
VD0004 00:50:56:90:57:1e
VD0005 00:50:56:90:57:1f

Scan the logfile for any problems in the top section. The data after “Replaced MAC addresses:” is what the PVS server needs. Copy this over to the PVS host. Now we need to use MCLIPSSnapin, but first we have to register the DLL. I followed this Citrix blog for syntax:
“C:\Windows\Microsoft.NET\Framework64\v2.0.50727\installutil.exe” “C:\Program Files\Citrix\Provisioning Services Console\McliPSSnapIn.dll”

I copied the VM names and new MAC addresses to a text file vmlist.txt and put it on my PVS server, in the same folder as the following PowerShell script. It runs very quickly, it takes only a few seconds even if you are updating hundreds of VMs.

Add-PSSnapIn mclipssnapin
$vmlist = get-content "vmlist.txt"
foreach ($row in $vmlist)
{
	$vmname=$row.Split(" ")[0]
	$macaddress=$row.Split(" ")[1]
	$vmname
	$macaddress
	Mcli-Set Device –p devicename=$vmname –r devicemac=$macaddress
}

Now, replace the PVS pool’s image with one that is prepared for a VMXNET3 adapter and boot the pool. Migration complete!