Smart Disk Defragmentation with Powershell
Published 2.23.2007 by ~mattg
As I mentioned before, I wrote a powershell script that defragments you hard drives based on a percentage. The nice thing about this is you can schedule this to run at a given interval (daily, weekly, whatever) and it will on defragment your drives as necessary. I gave a short synopsis of the process in the previous post, so I’ll just post the code here.
The main script is as such:
foreach ($drive in Get-WMIObject Win32_LogicalDisk -filter “DriveType = 3″)
{
$strDriveLetter = $drive.DeviceID
$strReport = defrag $strDriveLetter -a
$dFragPercent = [double] (Get-FragmentationPercent $strReport)
if ($dFragPercent -gt $dLimit)
{
echo “Drive $strDriveLetter defragmenting:”
echo “ Before: $dFragPercent% fragmented.”
$strDefragReport = defrag $strDriveLetter
$dNewFrag = Get-FragmentationPercent $strDefragReport $false
echo “ After: $dNewFrag% fragmented.”
}
else
{
echo “Drive $strDriveLetter does not need defragmented ($dFragPercent% fragmented)”
}
}
You may notice the Get-FragmentationPercent function. You can either put it in the same script file (before the main script), or in it’s own file with the Get-FragmentatinoPercent.ps1 filename.
{
param ($strReport, [bool] $bGetAnalysis=$true)
begin
{
$bInAnalysis = $false
$bInDefrag = $false
foreach ($line in $strReport)
{
if ($line -match “Analysis Report”)
{
$bInDefrag = $false;
$bInAnalysis = $true;
}
if ($line -match “Defragmentation Report”)
{
$bInAnalysis = $false;
$bInDefrag = $true;
}
if ($line -match “(?<percentfragmented>\d+)%\sFragmented\s”)
{
if (($bInAnalysis -and $bGetAnalysis) -or ($bInDefrag -and !$bGetAnalysis))
{
return $matches[“percentFragmented”]
}
}
}
return 0
}
}
I’ve been using this for a couple weeks with no problems. Just throw it in a script file and run. It looks at the first argument you pass it (parsing it as a double) and compares the defragmentation percentage to that limit. If the defrag percent is greater than your defined limit, it defrags the drive.
Filed under Windows
