DismountDVD.ps1

$clusterName = 'YourCLusterName'
Get-VM -computername (Get-ClusterNode -Cluster $clusterName).Name | 
    Get-VMDvdDrive | 
    Where-Object {$null -ne $_.Path} | 
    Select-Object VMName,ComputerName,Path |
    Out-GridView -PassThru | ForEach-Object { 
        Set-VMDvdDrive -Path $null -ComputerName $PSItem.ComputerName -VMName $PSItem.VMName -Passthru
    }