21 November 2013

Get VMs by Virtual Port Group with PowerCLI

How to find out what VMs use a particular virtual port group, and quickly?  Well, we have just the thing.  And, it also helps to illustrate the practical use of LinkedViews and the UpdateViewData() method of .NET View objects (about which we posted a while back in Even Faster PowerCLI Code with Get-View, UpdateViewData() and LinkedViews), along with the kind of speed increase that said method brings.

So, the function:
<#  .Description
    Function to get info about what VMs are on a virtual portgroup.  vNugglets, Oct 2013
    Highlights the use of the UpdateViewData() method of a .NET View object
function Get-VMOnNetworkPortGroup {
        ## name of network to get; regex pattern
    ) ## end param

    ## get the .NET View objects for the network port groups whose label match the given name
    $arrNetworkViews = Get-View -ViewType Network -Property Name -Filter @{"Name" = $NetworkName_str}
    if (($arrNetworkViews | Measure-Object).Count -eq 0) {Write-Warning "No networks found matching name '$NetworkName_str'"; exit}

    ## get the networks' VMs' names, along with the name of the corresponding VMHost and cluster
    $arrNetworkViews | %{$_.UpdateViewData("Vm.Name","Vm.Runtime.Host.Name","Vm.Runtime.Host.Parent.Name")}
    ## create a new object for each VM on this network
    $arrNetworkViews | %{
        $viewNetwk = $_
        $viewNetwk.LinkedView.Vm | %{
            New-Object -TypeName PSObject -Property @{
                VMName = $_.Name
                NetworkName = $viewNetwk.Name
                VMHost = $_.Runtime.LinkedView.Host.Name
                Cluster = $_.Runtime.LinkedView.Host.LinkedView.Parent.Name
            } | Select-Object VMName,NetworkName,VMHost,Cluster
        } ## end foreach-object
    } ## end foreach-object
} ## end fn
And, some sample usage:
PS vN:\> Get-VMOnNetworkPortGroup -NetworkName "223|237"

VMName        NetworkName   VMHost           Cluster
------        -----------   ------           -------
dubuntu0      223.Prod      esxi01.dom.com   Cluster0
vma5          223.Prod      esxi02.dom.com   Cluster0
vcsa02        223.Prod      esxi02.dom.com   Cluster0
tmpl_test1    237.Dev       esxi12.dom.com   Cluster1
This illustrates the use of a regular expression pattern to match virtual networks whose names contain "223" or "237".

And, on the topic of speed increases:
## using standard cmdlets:
PS vN:\> Measure-Command {Get-VirtualPortGroup -Name SomeNetworkName | Get-VM | select name,@{n="VMHostName"; e={$_.VMHost.name}},@{n="ClusterName"; e={$_.VMHost.Parent.Name}}}
TotalSeconds      : 25.4870345

## using vNugglets function:
PS vN:\> Measure-Command {Get-VMOnNetworkPortGroup -NetworkName SomeNetworkName}
TotalSeconds      : 0.9676149      ## big winner!

So, while similar results can be had with native PowerCLI cmdlets, leveraging this function definitely comes in handy, especially when you are as impatient as we can be here at vNugglets.  Enjoy!