WMI over WSMAN

Every time I look at PowerShell v3 I seem to find a new way to access WMI!

I’ve covered the –ComputerName and –CimSession parameters before but to recap

We duplicate the way Get-WmiObject works:

$computer = $env:COMPUTERNAME
Get-CimInstance -ClassName Win32_OperatingSystem -ComputerName $computer

We can use CIM sessions
$cs = New-CimSession -ComputerName $computer
Get-CimInstance -ClassName Win32_OperatingSystem -CimSession $cs

One little known and little used capability in PowerShell v2 was the WSMAN cmdlets. These enable us to access WMI directly over WSMAN

$ruri = "http://schemas.microsoft.com/wbem/wsman/1/wmi/root/cimv2/Win32_OperatingSystem"
Get-WSManInstance -ResourceURI $ruri -ComputerName $computer

This is fine for a single returned instance but where there are multiples eg disks we need to do a bit more work

$ruri = http://schemas.microsoft.com/wbem/wsman/1/wmi/root/cimv2/Win32_LogicalDisk

Get-WSManInstance -ResourceURI $ruri -ComputerName $computer -Enumerate |
select DeviceId, Description

It turns out that we can use these ResourceURIs with Get-CimInstance

$ruri = http://schemas.microsoft.com/wbem/wsman/1/wmi/root/cimv2/Win32_OperatingSystem

Get-CimInstance -ResourceUri $ruri -ComputerName $computer
Get-CimInstance -ResourceUri $ruri -CimSession $cs

Better still if we are going after multiple instances

$ruri = "http://schemas.microsoft.com/wbem/wsman/1/wmi/root/cimv2/Win32_LogicalDisk"
Get-CimInstance -ResourceUri $ruri -ComputerName $computer |
select DeviceId, Description

Get-CimInstance -ResourceUri $ruri -CimSession $cs |
select DeviceId, Description

You have to use –ComputerName OR –CimSession if you use –ResourceURI.  If you don’t you make a DCOM connection to the local machine and you request will fail. You also won’t be able to use –ResourceURI if your CIM session is over DCOM