Finding Large Directories and Recovering Lost Disk Space with PowerShell

LainRobertson shares a PowerShell module and examples for analyzing large directories and recovering lost disk space, offering practical insights for Windows administrators and developers.

Finding Large Directories and Recovering Lost Disk Space with PowerShell

Author: LainRobertson

Overview

When disk space mysteriously vanishes on Windows, GUI tools exist to help—but for automation and repeatable troubleshooting, PowerShell shines. This guide walks through using a simple PowerShell module to determine which directories are consuming the most space, leveraging .NET classes for efficiency and resilience.

XTree.psm1 PowerShell Module

Key Functions:

• Get-DirectorySize: Calculates the number and total size of files in a single directory.
• Get-DirectoryTreeSize: Recursively assesses directories, skipping reparse points to avoid double-counting or misattribution of files.

Module Code

function Get-DirectorySize {
    [cmdletbinding()]
    param(
        [parameter(Mandatory = $true)][ValidateNotNull()][string] $Path
    )

    Write-Verbose -Message "Parsing $Path";
    $Summary = [PSCustomObject] @{ Path = $Path.ToLowerInvariant(); Count = 0; Size = 0; }
    [System.IO.Directory]::EnumerateFiles($Path) | ForEach-Object {
        [System.IO.FileInfo]::new(---
layout: "post"
title: "Finding Large Directories and Recovering Lost Disk Space with PowerShell"
description: "This practical guide by LainRobertson demonstrates how to identify large directories and analyze disk space usage using a custom PowerShell module. The post explains the reasoning behind the approach, shares complete code examples, and walks through real-world use cases for filesystem analysis and troubleshooting in Windows environments."
author: "LainRobertson"
excerpt_separator: <!--excerpt_end-->
canonical_url: "https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117"
viewing_mode: "external"
feed_name: "Microsoft Tech Community"
feed_url: https://techcommunity.microsoft.com/t5/s/gxcuf89792/rss/Community
date: 2025-08-13 12:30:08 +00:00
permalink: "2025-08-13-Finding-Large-Directories-and-Recovering-Lost-Disk-Space-with-PowerShell.html"
categories: ["Coding"]
tags: [".NET", "Automation", "Coding", "Community", "Directory Size", "Disk Space Management", "Filesystem Analysis", "Get DirectorySize", "Get DirectoryTreeSize", "Module Development", "PowerShell", "Reparse Points", "Scripting", "System.IO.Directory", "Windows"]
tags_normalized: [["net", "automation", "coding", "community", "directory size", "disk space management", "filesystem analysis", "get directorysize", "get directorytreesize", "module development", "powershell", "reparse points", "scripting", "system dot io dot directory", "windows"]]
---

LainRobertson shares a PowerShell module and examples for analyzing large directories and recovering lost disk space, offering practical insights for Windows administrators and developers.<!--excerpt_end-->



This post appeared first on "Microsoft Tech Community". [Read the entire article here](https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117)
) | ForEach-Object {
            $Summary.Count++;
            $Summary.Size += ---
layout: "post"
title: "Finding Large Directories and Recovering Lost Disk Space with PowerShell"
description: "This practical guide by LainRobertson demonstrates how to identify large directories and analyze disk space usage using a custom PowerShell module. The post explains the reasoning behind the approach, shares complete code examples, and walks through real-world use cases for filesystem analysis and troubleshooting in Windows environments."
author: "LainRobertson"
excerpt_separator: <!--excerpt_end-->
canonical_url: "https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117"
viewing_mode: "external"
feed_name: "Microsoft Tech Community"
feed_url: https://techcommunity.microsoft.com/t5/s/gxcuf89792/rss/Community
date: 2025-08-13 12:30:08 +00:00
permalink: "2025-08-13-Finding-Large-Directories-and-Recovering-Lost-Disk-Space-with-PowerShell.html"
categories: ["Coding"]
tags: [".NET", "Automation", "Coding", "Community", "Directory Size", "Disk Space Management", "Filesystem Analysis", "Get DirectorySize", "Get DirectoryTreeSize", "Module Development", "PowerShell", "Reparse Points", "Scripting", "System.IO.Directory", "Windows"]
tags_normalized: [["net", "automation", "coding", "community", "directory size", "disk space management", "filesystem analysis", "get directorysize", "get directorytreesize", "module development", "powershell", "reparse points", "scripting", "system dot io dot directory", "windows"]]
---

LainRobertson shares a PowerShell module and examples for analyzing large directories and recovering lost disk space, offering practical insights for Windows administrators and developers.<!--excerpt_end-->



This post appeared first on "Microsoft Tech Community". [Read the entire article here](https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117)
.Length;
        }
    }
    $Summary;
}

function Get-DirectoryTreeSize {
    [cmdletbinding()]
    param(
        [parameter(Mandatory = $true)][ValidateNotNull()][string] $Path
    )

    # Reference: https://learn.microsoft.com/en-us/dotnet/api/system.io.fileattributes?view=netframework-4.8.1
    New-Variable -Name "ReparsePoint" -Value ([System.IO.FileAttributes]::ReparsePoint.value__) -Option Constant;
    $Summary = [PSCustomObject] @{ Path = $Path.ToLowerInvariant(); Count = 0; Size = 0; TotalCount = 0; TotalSize = 0; }
    [System.IO.Directory]::EnumerateDirectories($Path) | ForEach-Object {
        # Avoid processing reparse points.
        if (0 -eq (([System.IO.DirectoryInfo]::new(---
layout: "post"
title: "Finding Large Directories and Recovering Lost Disk Space with PowerShell"
description: "This practical guide by LainRobertson demonstrates how to identify large directories and analyze disk space usage using a custom PowerShell module. The post explains the reasoning behind the approach, shares complete code examples, and walks through real-world use cases for filesystem analysis and troubleshooting in Windows environments."
author: "LainRobertson"
excerpt_separator: <!--excerpt_end-->
canonical_url: "https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117"
viewing_mode: "external"
feed_name: "Microsoft Tech Community"
feed_url: https://techcommunity.microsoft.com/t5/s/gxcuf89792/rss/Community
date: 2025-08-13 12:30:08 +00:00
permalink: "2025-08-13-Finding-Large-Directories-and-Recovering-Lost-Disk-Space-with-PowerShell.html"
categories: ["Coding"]
tags: [".NET", "Automation", "Coding", "Community", "Directory Size", "Disk Space Management", "Filesystem Analysis", "Get DirectorySize", "Get DirectoryTreeSize", "Module Development", "PowerShell", "Reparse Points", "Scripting", "System.IO.Directory", "Windows"]
tags_normalized: [["net", "automation", "coding", "community", "directory size", "disk space management", "filesystem analysis", "get directorysize", "get directorytreesize", "module development", "powershell", "reparse points", "scripting", "system dot io dot directory", "windows"]]
---

LainRobertson shares a PowerShell module and examples for analyzing large directories and recovering lost disk space, offering practical insights for Windows administrators and developers.<!--excerpt_end-->



This post appeared first on "Microsoft Tech Community". [Read the entire article here](https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117)
).Attributes.value__ -band $ReparsePoint))) {
            Get-DirectoryTreeSize -Path ---
layout: "post"
title: "Finding Large Directories and Recovering Lost Disk Space with PowerShell"
description: "This practical guide by LainRobertson demonstrates how to identify large directories and analyze disk space usage using a custom PowerShell module. The post explains the reasoning behind the approach, shares complete code examples, and walks through real-world use cases for filesystem analysis and troubleshooting in Windows environments."
author: "LainRobertson"
excerpt_separator: <!--excerpt_end-->
canonical_url: "https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117"
viewing_mode: "external"
feed_name: "Microsoft Tech Community"
feed_url: https://techcommunity.microsoft.com/t5/s/gxcuf89792/rss/Community
date: 2025-08-13 12:30:08 +00:00
permalink: "2025-08-13-Finding-Large-Directories-and-Recovering-Lost-Disk-Space-with-PowerShell.html"
categories: ["Coding"]
tags: [".NET", "Automation", "Coding", "Community", "Directory Size", "Disk Space Management", "Filesystem Analysis", "Get DirectorySize", "Get DirectoryTreeSize", "Module Development", "PowerShell", "Reparse Points", "Scripting", "System.IO.Directory", "Windows"]
tags_normalized: [["net", "automation", "coding", "community", "directory size", "disk space management", "filesystem analysis", "get directorysize", "get directorytreesize", "module development", "powershell", "reparse points", "scripting", "system dot io dot directory", "windows"]]
---

LainRobertson shares a PowerShell module and examples for analyzing large directories and recovering lost disk space, offering practical insights for Windows administrators and developers.<!--excerpt_end-->



This post appeared first on "Microsoft Tech Community". [Read the entire article here](https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117)
 | ForEach-Object {
                $Summary.TotalCount += ---
layout: "post"
title: "Finding Large Directories and Recovering Lost Disk Space with PowerShell"
description: "This practical guide by LainRobertson demonstrates how to identify large directories and analyze disk space usage using a custom PowerShell module. The post explains the reasoning behind the approach, shares complete code examples, and walks through real-world use cases for filesystem analysis and troubleshooting in Windows environments."
author: "LainRobertson"
excerpt_separator: <!--excerpt_end-->
canonical_url: "https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117"
viewing_mode: "external"
feed_name: "Microsoft Tech Community"
feed_url: https://techcommunity.microsoft.com/t5/s/gxcuf89792/rss/Community
date: 2025-08-13 12:30:08 +00:00
permalink: "2025-08-13-Finding-Large-Directories-and-Recovering-Lost-Disk-Space-with-PowerShell.html"
categories: ["Coding"]
tags: [".NET", "Automation", "Coding", "Community", "Directory Size", "Disk Space Management", "Filesystem Analysis", "Get DirectorySize", "Get DirectoryTreeSize", "Module Development", "PowerShell", "Reparse Points", "Scripting", "System.IO.Directory", "Windows"]
tags_normalized: [["net", "automation", "coding", "community", "directory size", "disk space management", "filesystem analysis", "get directorysize", "get directorytreesize", "module development", "powershell", "reparse points", "scripting", "system dot io dot directory", "windows"]]
---

LainRobertson shares a PowerShell module and examples for analyzing large directories and recovering lost disk space, offering practical insights for Windows administrators and developers.<!--excerpt_end-->



This post appeared first on "Microsoft Tech Community". [Read the entire article here](https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117)
.Count;
                $Summary.TotalSize += ---
layout: "post"
title: "Finding Large Directories and Recovering Lost Disk Space with PowerShell"
description: "This practical guide by LainRobertson demonstrates how to identify large directories and analyze disk space usage using a custom PowerShell module. The post explains the reasoning behind the approach, shares complete code examples, and walks through real-world use cases for filesystem analysis and troubleshooting in Windows environments."
author: "LainRobertson"
excerpt_separator: <!--excerpt_end-->
canonical_url: "https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117"
viewing_mode: "external"
feed_name: "Microsoft Tech Community"
feed_url: https://techcommunity.microsoft.com/t5/s/gxcuf89792/rss/Community
date: 2025-08-13 12:30:08 +00:00
permalink: "2025-08-13-Finding-Large-Directories-and-Recovering-Lost-Disk-Space-with-PowerShell.html"
categories: ["Coding"]
tags: [".NET", "Automation", "Coding", "Community", "Directory Size", "Disk Space Management", "Filesystem Analysis", "Get DirectorySize", "Get DirectoryTreeSize", "Module Development", "PowerShell", "Reparse Points", "Scripting", "System.IO.Directory", "Windows"]
tags_normalized: [["net", "automation", "coding", "community", "directory size", "disk space management", "filesystem analysis", "get directorysize", "get directorytreesize", "module development", "powershell", "reparse points", "scripting", "system dot io dot directory", "windows"]]
---

LainRobertson shares a PowerShell module and examples for analyzing large directories and recovering lost disk space, offering practical insights for Windows administrators and developers.<!--excerpt_end-->



This post appeared first on "Microsoft Tech Community". [Read the entire article here](https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117)
.Size;
                ---
layout: "post"
title: "Finding Large Directories and Recovering Lost Disk Space with PowerShell"
description: "This practical guide by LainRobertson demonstrates how to identify large directories and analyze disk space usage using a custom PowerShell module. The post explains the reasoning behind the approach, shares complete code examples, and walks through real-world use cases for filesystem analysis and troubleshooting in Windows environments."
author: "LainRobertson"
excerpt_separator: <!--excerpt_end-->
canonical_url: "https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117"
viewing_mode: "external"
feed_name: "Microsoft Tech Community"
feed_url: https://techcommunity.microsoft.com/t5/s/gxcuf89792/rss/Community
date: 2025-08-13 12:30:08 +00:00
permalink: "2025-08-13-Finding-Large-Directories-and-Recovering-Lost-Disk-Space-with-PowerShell.html"
categories: ["Coding"]
tags: [".NET", "Automation", "Coding", "Community", "Directory Size", "Disk Space Management", "Filesystem Analysis", "Get DirectorySize", "Get DirectoryTreeSize", "Module Development", "PowerShell", "Reparse Points", "Scripting", "System.IO.Directory", "Windows"]
tags_normalized: [["net", "automation", "coding", "community", "directory size", "disk space management", "filesystem analysis", "get directorysize", "get directorytreesize", "module development", "powershell", "reparse points", "scripting", "system dot io dot directory", "windows"]]
---

LainRobertson shares a PowerShell module and examples for analyzing large directories and recovering lost disk space, offering practical insights for Windows administrators and developers.<!--excerpt_end-->



This post appeared first on "Microsoft Tech Community". [Read the entire article here](https://techcommunity.microsoft.com/t5/windows-powershell/how-to-finding-large-directories-recovering-lost-space/m-p/4442877#M9117)
;
            }
        }
    }
    $Stats = Get-DirectorySize -Path $Path;
    $Summary.Count = $Stats.Count;
    $Summary.Size = $Stats.Size;
    $Summary.TotalCount += $Stats.Count;
    $Summary.TotalSize += $Stats.Size;
    $Summary;
}

Export-ModuleMember -Function @("Get-DirectorySize", "Get-DirectoryTreeSize");

Usage Examples

1. Top Five Consumers by TotalSize

Useful for understanding the largest overall subdirectories in a tree:

Get-DirectoryTreeSize -Path "D:\Data\Temp\Edge\windows" |
    Sort-Object -Property TotalSize -Descending |
    Select-Object -First 5 |
    Format-Table -AutoSize -Property TotalSize, TotalCount, Path

2. Top Five Consumers by Size

Helps target the largest single directories (excluding nested items):

Get-DirectoryTreeSize -Path "D:\Data\Temp\Edge\windows" |
    Sort-Object -Property Size -Descending |
    Select-Object -First 5 |
    Format-Table -AutoSize -Property Size, Count, Path

Why Avoid Reparse Points?

• Avoids double-counting files if they are referenced multiple times.
• Prevents including data from outside the target tree, ensuring accurate metrics.

Implementation Notes

• Uses [System.IO.Directory] for better performance versus Get-ChildItem.
• Get-ChildItem can throw errors on reparse points; this approach dodges that.
• For illustration: Get-ChildItem -Directory -Force -Path "$env:USERPROFILE\Application Data\";

Summary

This approach provides a pragmatic, replicable method for diagnosing disk space issues on Windows systems using PowerShell. By adopting built-in .NET functionality and careful logic around reparse points, it’s robust and especially useful for IT pros and developers seeking scriptable answers.

This post appeared first on “Microsoft Tech Community”. Read the entire article here