VM power state not updated and returned correctly

Question

I'm trying to power on VMs which I previously powered off using PowerCLI.
When I try to run the following script (part of a bigger one) I still get a status which is not "PoweredOn", even though I can see on the VSphere console that the machine was powered on.
I get this also in other situations and I try to re-get the virtual machines, but I fail to make this work.
If I don't re-get the VMs, I sometimes get error claiming the VM I'm referring to is null. What am I doing wrong? What am I missing?
Here are the script lines:

$VMs = get-vm | Where-object {($_.Name -like $vmNamePatternToSearch)}# | Out-Null
foreach ($vm in $VMs) {
    #$vm = Get-VM -Name $vm.Name #| Out-Null
    if ($vm.powerstate -ieq "poweredoff") {
        Start-VM -VM $vm -Confirm:$False | Out-Null
        Write-Host -NoNewline 'Powering On' $vm.Name.ToString().PadRight(22)
        do {
            Start-Sleep -Seconds 1
            Write-Host -NoNewline '|' $vm.powerstate
        } until ($vm.powerstate -ieq "PoweredOn")
        Write-Host
    }
}

So my output is "| PoweredOff| PoweredOff| PoweredOff| PoweredOff| PoweredOff|..."
Even though the machine is already up.
Even if I un-comment the "#$vm = Get-VM -Name $vm.Name #| Out-Null" line - still no go.

I would appreciate your input.

Thanks!

Answer 1

PowerShell's objects are point in time references. So your vm variable will continue to reflect the status of the VM at the time you ran the get-vm cmdlet.

To help overcome this you could run something like the following to reference the updated state of the VM during your loop:

        do {
            Start-Sleep -Seconds 1
            Write-Host -NoNewline '|' $vm.powerstate
        } until ((Get-VM $vm).powerstate -ieq "PoweredOn")