BlobMounter

Mount Azure Blob Storage containers as Windows drive letters. Browse, read, write, and manage blobs directly from Windows Explorer.

Features

• Mount any Azure Blob Storage container as a local drive letter (e.g. Z:)
• Full read/write support — create, edit, rename, and delete files
• Optional read-only mode
• Mount a subfolder within a container
• Metadata caching for responsive directory browsing
• Connection settings saved between sessions (account key encrypted with Windows DPAPI)
• Simple single-window WPF interface

Prerequisites

1. Windows 10/11
2. .NET 8 Runtime (or SDK to build from source)
3. Dokan driver v2.x — install DokanSetup.exe from the latest release

Getting Started

Build from source

git clone https://github.com/andybochmann/blob-mounter.git
cd blob-mounter
dotnet build
dotnet run --project src/BlobMounter.App

Usage

1. Launch the application
2. Enter your Azure Storage Account Name and Account Key
3. Enter the Container name (and optionally a Subfolder prefix)
4. Select an available Drive Letter
5. Click Test Connection to verify credentials
6. Click Mount
7. Open the mounted drive in Windows Explorer

To disconnect, click Unmount next to the drive in the app.

Architecture

BlobMounter.sln
src/
  BlobMounter.Core/          # File system + Azure logic (no UI dependencies)
    Azure/                   # Azure SDK wrapper, path mapping, metadata cache
    FileSystem/              # DokanNet IDokanOperations implementation
    Models/                  # Data models

  BlobMounter.App/           # WPF application
    ViewModels/              # MVVM with CommunityToolkit.Mvvm
    Services/                # Mount orchestration, driver detection, settings

  BlobMounter.Tests/         # Unit tests (xUnit)

How it works

BlobMounter uses DokanNet to create a virtual file system that translates Windows file operations into Azure Blob Storage API calls:

• Directory listing maps to GetBlobsByHierarchy with / delimiter
• File read downloads the full blob into a memory buffer on first access
• File write buffers changes in memory and uploads on file close
• Rename is implemented as server-side copy + delete (blob storage has no native rename)
• Delete directory recursively deletes all blobs with the matching prefix

A 30-second metadata cache reduces API calls when browsing directories.

Known Limitations

• No file locking (Azure Blob Storage limitation)
• Rename/move of large files is slow (copy + delete)
• Files are fully downloaded on open — large files (>100 MB) use temp disk storage
• Blob names are case-sensitive; Windows paths are not — avoid name collisions
• Virtual directories have synthetic timestamps

Running Tests

dotnet test

License

MIT