Pin a file

Hi,

Im having trouble pinning a file to the HDD tier of a server 2012 r2 storage spaces pool.

Tried http://technet.microsoft.com/en-us/library/dn454976.aspx without luck.

$hddtier = Get-StorageTier -FriendlyName "local_Microsoft_HDD_Template"

Set-FileStorageTier -DesiredStorageTierUniqueId $StorageTier.uniqueid -FilePath "D:\touch.txt"

Set-FileStorageTier : Cannot bind argument to parameter 'DesiredStorageTierUniqueId' because it is an empty string.
At line:1 char:49
+ Set-FileStorageTier -DesiredStorageTierUniqueId $StorageTier.uniqueid -FilePath  ...
+                                                 ~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidData: (:) [Set-FileStorageTier], ParameterBindingValidationException
    + FullyQualifiedErrorId : ParameterArgumentValidationErrorEmptyStringNotAllowed,Set-FileStorageTier