BTW, some may find it useful to use the VMWare credential store, as opposed to storing their credentials in a script, here’s the connection string I have based on this:

http://communities.vmware.com/thread/199583

C:\WINDOWS\system32\windowspowershell\v1.0\powershell.exe -PSConsoleFile “C:\Program Files\VMware\Infrastructure\VSphere PowerCLI\vim.psc1” -NoExit –Command
$creds = Get-VICredentialStoreItem -Host ‘yourhost’
Connect-VIServer -Server yourserver -User $creds.User -Password $creds.Password
# Connect to the VC server credential store

# For each of the VMs on the ESX hosts
Foreach ($VM in ($ESXSRV | Get-VM | Where { $_.PowerState -eq “poweredOn” } | Where { $_.Name -ne “VCENTER” })){

# Stop all VM’s in a RP

do

{
# Get the name of the Resource Pool
$ResourcePool = read-host ” Insert the Name of the Resource Pool to Stop”
# Get the members of that RP
$VMName = (get-resourcepool $ResourcePool | get-vm)
# For each of the VMs in the RP
{
Foreach ($VMName in ($ResourcePool | get-vm | Where-object {$_.PowerState -eq “poweredOn” }))
}
# Shutdown the guest cleanly
{$VMName | Stop-VM -Confirm:$false}
}
until ($script:response -eq “quit”);

Start-Transcript -Path C:\CSS_Log.txt -Append

Add-PSSnapin VMware.VimAutomation.Core
Set-PowerCLIConfiguration -DefaultVIServerMode multiple -Confirm:$False

Connect-VIServer HOSTA,HOSTB,HOSTC -User ‘USER’ -Password ‘PASSWORD’
Get-VMHost | Get-VMHostStartPolicy | Set-VMHostStartPolicy -Enabled:$True -WaitForHeartBeat:$True
Get-VM | Get-VMStartPolicy | Set-VMStartPolicy -StartAction PowerOn -UnspecifiedStartOrder
Get-VM -Name SVR-SQL01 | Get-VMStartPolicy | Set-VMStartPolicy -StartAction PowerOn -StartOrder 3
Get-VM -Name SVR-VC01 | Get-VMStartPolicy | Set-VMStartPolicy -StartAction PowerOn -StartOrder 2
Get-VM -Name SVR-DC01 | Get-VMStartPolicy | Set-VMStartPolicy -StartAction PowerOn -StartOrder 1
Get-VM | Shutdown-VMGuest -Confirm:$False
DO {Get-VM | Get-VMGuest} WHILE (Get-VM | Get-VMGuest | where {$_.State -eq “Running”})
Get-VM | Stop-VM -Confirm:$False
DO {Get-VM} WHILE (Get-VM | where {$_.PowerState -eq “PoweredOn”})
Get-VMHost | Stop-VMHost -Force -Confirm:$False

Stop-Transcript

Also be aware that any shutdown will not work on ESXi.
As They have disabled write access to the host.

So I’m in the process of writing a shutdown application to get around this new limitation and will be posting on my blog when done if anyone interested.

thank you for your advice.i added the flowing code to my script
if (!(get-pssnapin -name VMware.VimAutomation.Core -erroraction silentlycontinue)) {
Write-Host “add-pssnapin …”
add-pssnapin VMware.VimAutomation.Core
}else{
Write-Host “already exist.no need to add”
}
it shows “already exist.no need to add”.and no output from get-vm cmdlet.

I’m looking at shutting down a ESXi host with running guests.
The guests should get automaticaly shutdown by the host if configured correctly.
So just need to shutdown the host cleanly.
Also need to shut down another FreeNAS box, but that’s another story.
Been playing with a few scripts, then saw one in the vSphere PowerCLI Administration Guide on pg 14:
Downloadable from here http://www.vmware.com/support/developer/PowerCLI/PowerCLI41U1/html/index.html
5 Shut down the myHost virtual machine host
$host = Get-VMHost myHost
$hv = Get-View $h.ID
$hv.ShutdownHost_Task($true)
Any one got any idea what the $h is?
Also when I run the first line in PowerGUI Script Editor I get:
Cannot overwrite variable Host because it is read-only or constant.
At C:\Users\user\AppData\Local\Temp\7aad3dc5-990e-4568-a06b-987092d00575.ps1:5 char:6
+ $host <<<< = Get-VMHost $vSphereServername
+ CategoryInfo : WriteError: (Host:String) [], SessionStateUnauthorizedAccessException
+ FullyQualifiedErrorId : VariableNotWritable

Then for the second line I get:
Get-View : Cannot validate argument on parameter 'VIObject'. The argument is null or empty. Supply an argument that is not null or empty and then try the
command again.
At C:\Users\user\AppData\Local\Temp\7aad3dc5-990e-4568-a06b-987092d00575.ps1:6 char:15
+ $hv = Get-View <<<< $h.ID

I've already established connection to the host by way of Connect-VIServer.
Anyone got any ideas?