I made a blog post some time ago, where i created a powerCLI function for creating a VM affinity rule that would keep my VM´s in a vApp together in the cluster for better VM-VM performance. I then checked for MoRef to get the VM correlated between vCloud Director and vCenter.

The answer to my problem was much closer than I thought, the vCloud director creates a folder in the “VM´s and Template view” for each vApp and guess what, all VM´s are in there.. so I do not need to ask the vCloud Director anymore (well if I want the Cloud vApp name I do need to ask it..) but ironically I had not looked there and found out that the folders actually where created for each deployed vCloud vApp :-/

So the code is a bit simpler and to get all VM´s from a folder I just type this, the asterisk is because the folder also gets a unique id

Get-Folder | where {$_.Name -like "ProdvCPod*"} | Get-VM

And then I just need to put those VM´s into an array and create a DRS rule, and here is the function that does this

<#
.Synopsis
   Add an affinity rule for a vCloud Director vAPP
.DESCRIPTION
   This function takes a vApp name (string) as parameter and creates an affinity rule for them to keep them together
.EXAMPLE
   Add-vAppAffinity -CIVApp ProdCust01
.NOTES
Author: Niklas Akerlund
Date: 2012-06-21
#>
function Add-vAppAffinity
{
    Param
    (
        # Parameter for the vAPP
        [Parameter(Mandatory=$true,
                   ValueFromPipelineByPropertyName=$true,
                   Position=0)]
        $CIVApp,

        # If the rule should apply on a different cluster
        $Cluster = "Cluster01"
    	)

	if ($CIVApp -ne " " -or $CIVApp -ne $null -or $CIVApp.length -ne 0 ){
		$Cluster = Get-Cluster $Cluster
		$VAppname = $CIVApp + "*"
		$VMs =  Get-Folder | where {$_.Name -like $VAppname} | Get-VM	
		
		if (!(Get-DrsRule -Cluster $Cluster -Name $CIVApp -ErrorAction SilentlyContinue)){ 
			New-DrsRule -Name $CIVApp -Cluster $Cluster -KeepTogether $true -VM $VMs
		}else{
			Remove-DrsRule -Rule (Get-DrsRule -Cluster $Cluster -Name $CIVApp) -Confirm:$false
			New-DrsRule -Name $CIVApp -Cluster $Cluster -KeepTogether $true -VM $VMs
		}
	}
}

To run it:

and it looks something like this if I check the cluster settings

preferably you have set your DRS cluster to fully automated or not so much will happen 🙂