How to Get Actual Hard Disk Memory of A VM? - powershell

Question

Is it possible to get the actual hard disk usage of a virtual machine?
Measure-VM -Name * | select-object -property TotalDiskAllocation
The TotalDiskAllocation property gets the total disk space assigned to the VM and even though this is helpful I also need to know how much is really being used.
For example, if a VM has 150 GB of allocated memory and it only uses 50 GB, is there any Powershell command that will be able to extract the 50 GB? If yes, how will I be able to incorporate that script to the script above?

Answer 1

Based on your attempt to use Measure-VM, I assumed you are using Hyper-V. I use something similar to this in one of my Hyper-V scripts:
(Get-VM dechiro1).HardDrives | ForEach {
$GetVhd = Get-VHD -Path $_.Path
[pscustomobject]#{
Name = $_.Name
Type = $GetVhd.VhdType
ProvisionedGB = ($GetVhd.Size / 1GB)
CommittedGB = ($GetVhd.FileSize / 1GB)
}
}
Basically, for each of the virtual machine's hard drives, use Get-VHD to get the VHD details which includes the full size and what I refer to as the committed size (actual space on disk).
Example output:
Name Type ProvisionedGB CommittedGB
---- ---- ------------- -----------
Hard Drive on IDE controll... Dynamic 20 0.00390625
Hard Drive on IDE controll... Dynamic 40 0.00390625
Edit:
If you wanted to pull from every VM and include the VM name with the returned object and you prefer to use the pipeline form, this will work:
Get-VM | ForEach { $Vm = $_; $_.HardDrives } | ForEach {
$GetVhd = Get-VHD -Path $_.Path
[pscustomobject]#{
Vm = $Vm.Name
Name = $_.Name
Type = $GetVhd.VhdType
ProvisionedGB = ($GetVhd.Size / 1GB)
CommittedGB = ($GetVhd.FileSize / 1GB)
}
}