fsGrowthMon.ps1: monitor filesystem growth at the subfolder level, and log to .csv

fsGrowthMon.ps1

# IMPORTANT: start this script in a fresh session to prevent previous exceptions from carrying over in $Error 

function folderClass
{
    param
    (
        [Parameter(Mandatory=$true)]
        [String]$path,
        [Parameter(Mandatory=$true)]
        [double]$origSize
    )
    $folderObj = @{}
    $folderObj.path = $path
    $folderObj.origSize = [math]::Round($($origSize/1024/1024),2) # all size props expressed in MB rounded to hundredths
    $folderObj.currSize = [math]::Round($($origSize/1024/1024),2) # intentional.  At object creation, $orig = $curr size.
    $folderObj.delta = $folderObj.currSize - $folderObj.origSize 
    $folderObj.isDirty = $false # toggles $true if gci throws exception (filname too long, insufficient permissions, etc.)
    $folderObj.exception = "None" # holds most recent gci exception for this folder

    return $folderObj
}


# config
$targetDir = "D:\Your\Target\Path\Here" # change this!
$folderObs = @()
$prevErrorCount = 0

# first pass: populate an array of folder objs with the properties we need to continually calculate size diffs
$folders = gci $targetDir
$folderCount = $folders.Count

foreach ($folder in $folders)
{

    $folderSize = gci $folder.FullName -Recurse | Measure-Object -property length -sum
    $currFolderObj = folderClass $folder.FullName $folderSize.Sum

    # try/catch will not work for the statements above, this is the only way to do it.
    if ($($Error.count) -gt $prevErrorCount)
    {
        $currFolderObj.isDirty = $true
        $errorIndex = $Error.Count - 1
        $currFolderObj.exception = $Error[$errorIndex].ToString()
        $prevErrorCount = $Error.Count    
    }

    $folderObs += $currFolderObj

    write-host "$($currFolderObj.path), size $($currFolderObj.currSize) MB"
    # $cont = read-host "any key to continue"
}

# subsequent passes: iterate over the folder objects, calculate size delta, and log out to .csv
while($true)
{
    # new output file for each iteration, so we can delete files easily
    $outFile = "$(Get-Date -f yyyy-MM-dd-HHmm).csv"
	New-Item $outFile -Type file | Out-Null
	"PATH,ORIG_SIZE,CURR_SIZE,DELTA,IS_DIRTY,MOST_RECENT_EXCEPTION" | Out-File $outFile -Append

    foreach ($folderObj in $folderObs)
    {
        $currFolderSize = gci $folderObj.path -Recurse | Measure-Object -property length -sum
        $folderObj.currSize = [math]::Round($($currFolderSize.sum/1024/1024),2)
        $folderObj.delta = [math]::Round($($folderObj.currSize - $folderObj.origSize),2)
        
	# try/catch will not work for the statements above, this is the only way to do it.
	if ($($Error.count) -gt $prevErrorCount)
	{
	    $currFolderObj.isDirty = $true
	    $errorIndex = $Error.Count - 1
	    $currFolderObj.exception = $Error[$errorIndex].ToString()
	    $prevErrorCount = $Error.Count    
	}

        write-host "$($folderObj.path), $($folderObj.origSize), $($folderObj.currSize), $($folderObj.delta), $($folderObj.isDirty), $($folderObj.exception)"
        "$($folderObj.path), $($folderObj.origSize), $($folderObj.currSize), $($folderObj.delta), $($folderObj.isDirty), $($folderObj.exception)" | Out-File $outFile -Append
    }
}