# WMI-DefragStats.ps1
# Uses WMI to get defrag statistics from the local C:
# Only tested on Longhorn - does not work on XP
# thomas lee - tfl@psp.co.uk

# get volumes on local system
$v = get-wmiobject win32_volume

# Display Number of volumes
"Number of volumes {0}: " -f $v.length

# Now get the C:\ volume
$v1=$v | where {$_.name -eq "C:\"}

# Perform a defrag analysis on the C: drive
"Performing Defrag Analysis"
$dfa = $v1.DefragAnalysis().DefragAnalysis

# Display results
"";"Defrag Results - defrag of C:"
"-----------------------------"

"Average File Size (KB) : {0} KB" -f ($dfa.AverageFileSize/1kb)
"Average Fragments per File : {0} " -f $dfa.averageFragmentsPerfile
"Average Free Space per Extent : {0} " -f $dfa.AverageFreeSpacePerExtent
"Cluster Size (KB) : {0} " -f ($dfa.clustersize/1KB)
"Excess Folder Fragments : {0} " -f $dfa.ExcessFolderFragments
"File Percent Fragementation : {0} " -f $dfa.FilePercentFragementation
"Fragmented folders : {0} " -f $dfa.FragmentedFolders
"Free Space (GB) : {0} GB" -f ($dfa.FreeSpace/1gb)
"Free Space Percent : {0} " -f $dfa.FreeSpacePercent
"Free Space Percent Fragementation : {0} " -f $dfa.FreeSpacePercentFragementaion
"Largest free Space Extent : {0} " -f $dfa.LargestFreeSpaceExtent
"MFT Percent In Use : {0} " -f $dfa.MFTPercentInUse
"MFT Record count : {0} " -f $dfa.MFTRecordCount
"Page File Size : {0} " -f $dfa.PageFileSize
"Total Excess Fragements : {0} " -f $dfa.TotalExcessFragements
"Total Files : {0} " -f $dfa.TotalFiles
"Total Folders : {0} " -f $dfa.TotalFolders
"Total Fragmented Files : {0} " -f $dfa.TotalFragmentedFiles
"Total Free Space Extents : {0} " -f $dfa.TotalFreeSpaceExtents
"Total MFT Fragments : {0} " -f $dfa.TotalMftFragments
"Total MFT Size : {0} " -f $dfa.TotalMftSize
"Total Page File Fragements : {0} " -f $dfa.TotalPageFileFragements
"Total Percent Fragementation : {0} " -f $dfa.TotalPercentFragementation
"Total Unmovable Files : {0} " -f $dfa.TotalUnmovableFiles
"Used Space (GB) : {0} GB" -f ($dfa.UsedSpace/1gb)
"Volume Name : {0} " -f $dfa.VolumeName
"Volume Size (GB) : {0} GB" -f ($dfa.VolumeSize/1gb)

On a Windows Server 2008 VM, this script returned the following output:

  
PS C:\Users\Administrator> .\wmi-defragstats.ps1
Number of volumes 2:
Performing Defrag Analysis

Defrag Results - defrag of C:
-----------------------------
Average File Size (KB) : 194.904296875 KB
Average Fragments per File : 1.04
Average Free Space per Extent : 66928900
Cluster Size (KB) : 4
Excess Folder Fragments : 0
File Percent Fragementation :
Fragmented folders : 1
Free Space (GB) : 55.9121589660645 GB
Free Space Percent : 87
Free Space Percent Fragementation :
Largest free Space Extent : 34251751424
MFT Percent In Use : 91
MFT Record count : 45363
Page File Size : 0
Total Excess Fragements :
Total Files : 37044
Total Folders : 8223
Total Fragmented Files : 14
Total Free Space Extents : 897
Total MFT Fragments : 2
Total MFT Size : 50790400
Total Page File Fragements :
Total Percent Fragementation :
Total Unmovable Files : 24
Used Space (GB) : 8.08490753173828 GB
Volume Name :
Volume Size (GB) : 63.9970664978027 GB
PS C:\Users\Administrator> 

Hey all, I've been hacking away at this for a few hours. Getting an OLE VT_DISPATCH object back as an out parameter is a lot trickier than I thought it would be. Hope it helps so that it doesn't take you as long! :-)

This has been tested and works like a charm in ActiveState Perl 5.8.8.

use Win32::OLE('in');
use Win32::OLE::Variant;

use constant wbemFlagReturnImmediately => 0x10;
use constant wbemFlagForwardOnly => 0x20;

%return_code = (
  0 => 'Success',
  1 => 'Access denied',
  2 => 'Not supported',
  3 => 'Volume dirty bit is set',
  4 => 'Not enough free space',
  5 => 'Corrupt master file table detected',
  6 => 'Call canceled',
  7 => 'Call cancellation request too late',
  8 => 'Defrag engine is already running',
  9 => 'Unable to connect to defrag engine',
  10 => 'Defrag engine error',
  11 => 'Unknown error',
);

$host = ".";
$objWMI = Win32::OLE->GetObject
  ("winmgmts:{impersonationLevel=impersonate}!\\\\$host\\root\\cimv2")
  or die "WMI connection failed.\n";

$colItems = $objWMI->ExecQuery("Select * from Win32_Volume where " .
  "DriveType = 3", "WQL", wbemFlagReturnImmediately | wbemFlagForwardOnly)
  or die "Unable to query.\n";

foreach $objItem (in $colItems)
{
  $df_recommended = Variant(VT_BOOL|VT_BYREF, 0);
  $df_a = Variant(VT_DISPATCH|VT_BYREF);
  $result = $objItem->DefragAnalysis($df_recommended, $df_a);
  $df_a = $df_a->Value();
  
  if ($result == 0) {  # Success
    print "Volume $objItem->{Name}\n";
    print " Defrag recommended:     ".($df_recommended ? "Yes" : "No")  ."\n";
    print " Average file size:      ".$df_a->{AverageFileSize}          ."\n";
    print " Total files:            ".$df_a->{TotalFiles}               ."\n";
    print " File fragmentation:     ".$df_a->{FilePercentFragmentation} ."\n";
    print " Used space:             ".$df_a->{UsedSpace}                ."\n";
    print " Free space:             ".$df_a->{FreeSpace}                ."\n";
    print " MFT percent in use:     ".$df_a->{MFTPercentInUse}          ."\n";
    # ...and whatever other properties you want to see
    print "\n";
  }
  else {
    print "Volume $objItem->{Name}\n";
    print "  " . $return_code{$result} . "\n";
    print "\n";
  }
}