Comparing two VMHostVirtualSwitches that always show equal

Question

I am comparing a predetermined object (VMHostVirtualSwitch Name) value with all object(VMHostVirtualSwitch Names) values within a collection of objects and want the status to be "FAIL" if the objects don't match

I have written the following code so far but it doesn't seem to be working. I know the objects don't match and I should get "FAIL" as an output

$VMHostVirtualSwitch = Get-VMHostNetwork -VMHost abc.com | Select-Object VirtualSwitch*
$Cluster = Get-Cluster -VMHost abc.com 
$VMHosts = Get-Cluster $Cluster | Get-VMHost
[int]$Switchcount=0

foreach ($VMHost in $VMHosts){
  $CurrentHostVirtualSwitch = Get-VMHostNetwork -VMHost $VMHost | Select-Object VirtualSwitch*
  if ($CurrentHostVirtualSwitch -ne $VMHostVirtualSwitch) {
   $Switchcount++
  }
}
if($Switchcount -ge 1) {
Write-Output "FAIL"
}

$VMHostVirtualSwitch has the following value

VirtualSwitch
-------------
{vSwitch3}

When I expand the $VMHostVirtualSwitch , I get the following values

Name                           NumPorts   Mtu   Notes                                             
----                           --------   ---   -----                                             
vSwitch3                       10562      2340

I can't tell but what is the type of `VirtualSwitch`? I ask because PowerShell might just be comparing types and not the object data. You might be better off expanding the property in both cases-> `| Select-Object -Expand VirtualSwitch` so you are working directly against the values. If the type does not support comparison operators you might still have to do this manually. — Matt, Jun 19 '18 at 19:17
I have edited my question and able to `Expand the value`. How can I just compare just the `VirtualSwitch Name`? — meallhour, Jun 19 '18 at 19:24
Ah ok. So that is the problem then. PowerShell does not know how to compare the objects. You could just expand the name as well. `Select-Object -expand VirtualSwitch | select-object -expand name` or `(Get-VMHostNetwork -VMHost abc.com).VirtualSwitch.Name` however could you get multiple switches returned? — Matt, Jun 19 '18 at 19:25

Matt · Accepted Answer · 2018-06-19T19:37:14.523

You problem is PowerShell does not know how to compare those objects. Even if they had the same data they are technically two different objects (a blog post touches on this subject). At the end of the day if you are just comparing the names then do your comparison on just those.

$VMHostVirtualSwitch = (Get-VMHostNetwork -VMHost abc.com).VirtualSwitch.Name
$Cluster = Get-Cluster -VMHost abc.com 
$VMHosts = Get-Cluster $Cluster | Get-VMHost
[int]$Switchcount=0

foreach ($VMHost in $VMHosts){
    $CurrentHostVirtualSwitch = (Get-VMHostNetwork -VMHost $VMHost).VirtualSwitch.Name
    if ($CurrentHostVirtualSwitch -ne $VMHostVirtualSwitch) {
        $Switchcount++
    }
}

if($Switchcount -ge 1) {
    Write-Output "FAIL"
}

Now you should just be comparing strings which will get you more predictable results. I have only change the variable expansion in the above example. You might have some error checking to do to account for.

Something like this might be shorter then your loop

$badHosts = $VMHosts | Where-Object{(Get-VMHostNetwork -VMHost $_).VirtualSwitch.Name -ne $VMHostVirtualSwitch}
if($badHosts.count -ge 1) {
    Write-Output "FAIL"
}

Compare-Object would also be a way to go for this, especially if there was multiple properties you were comparing: example. Since we are boiling down to simple strings I think what I propose should suffice.

I am at a loss to find the "article" that actually explains what is going on here. Basically VMware never gave PowerShell the knowledge on how to compare the objects you have here. — Matt, Jun 19 '18 at 19:44

Comparing two VMHostVirtualSwitches that always show equal

1 Answers1