Here’s a good powershell script that will help you to determine the content of a tape used by DPM.
$Lib = Get-DPMLibrary "Server-name"
$tpList = Get-Tape $Lib
foreach ($tp in $tpList)
$tp | fl label,barcode
Get-RecoveryPoint $Tp | fl
I can’t take fully credit for the design of this script, thanx M.