ManagedDrive

English

A Windows RAM disk manager built on .NET 10 and WinFsp.
Create, mount and manage in-memory volumes that appear as normal drive letters in Explorer.

Features

Mount multiple RAM disks simultaneously, each with its own drive letter
Configurable capacity, volume label and read-only flag
Dynamic memory allocation — disk capacity is a ceiling, not a reservation; memory is consumed only as files are written and released when files are deleted
Edit a mounted disk — change label, capacity, auto-mount, and image path live without data loss; changing the drive letter or read-only flag remounts the disk
Optional persistence — save the disk contents to a .mdr image file and restore it on next mount; Save Image is always available and prompts for a file path if none is set; the disk card shows a "Saving..." overlay while the save is in progress
Optional auto-save — periodically save the disk contents to its image file every 1–60 minutes (configurable when creating or editing a disk); a save also fires immediately when enabled and once more right before the disk is unmounted or the app exits, so nothing is lost between intervals. Periodic saves are skipped automatically when nothing has changed since the last save, avoiding unnecessary disk I/O on an idle disk. The image file must be selected through the file picker (no manual typing) and cannot be located on a RAM disk or reused across two disks. Checking Read Only, or clearing the selected image file, unchecks and disables auto-save (and Read Only also disables image compression) — a read-only disk's contents never change, so there is nothing to save or compress, an empty read-only disk would be meaningless, and auto-save has nothing to save to without an image file. The disk card shows the timestamp of the most recent content modification
Selectable image compression — choose a compression level (Off / Fast / Balanced / Max) for the saved .mdr image, trading save/load speed for file size; defaults to Fast
Auto-mount saved profiles on application startup
Double-click a disk card to open it in Explorer; right-click for Open in Explorer and Open Image File Directory (opens the folder containing the disk's .mdr image file; grayed out when the disk has no image file configured)
System-tray icon for quick access; minimizes to tray on window close
Tray icon tooltip — hover to see all mounted disks with live usage percentages
High-usage warning — system tray notification when a disk exceeds 90% capacity
Optional start-minimized mode — launch directly to tray without showing the main window
Temp directory redirection — right-click a disk to set it as the Windows TEMP/TMP directory; reset to the system default from the toolbar, context menu, or tray menu; automatically resets to the system default when the disk is unmounted or remounted; on startup, if TEMP/TMP points to any RAM disk profile a warning is shown — if the disk is not set to auto-mount, TEMP is also automatically reset to the system default
Exit confirmation — exiting the app (toolbar button or tray menu) while any disk is mounted brings the main window to the foreground and asks for confirmation; if TEMP/TMP points to any mounted RAM disk, the confirmation also warns that TEMP will be reset, and confirming resets it before exiting — system-initiated shutdown bypasses this prompt
NTFS-compatible volume identity — the RAM disk reports its filesystem type as NTFS, making it fully usable as a destination for tools that require an NTFS volume (e.g. WinGet, Windows Update staging, BITS downloads)
Format disk — right-click a disk and choose Format to delete all files and folders instantly (read-only disks are protected); the context menu is organized into three groups: navigation, configuration, and destructive operations
System tray menu — quick access to Reset Temp Directory (executes silently with a notification bubble result) and Settings in addition to Show, New Disk, and Exit
Main window opens centered on the primary screen and is brought to the foreground on startup
Bilingual UI — English and Simplified Chinese, auto-detected from system locale with manual override in Settings
Light and dark themes — follows the Windows app theme by default, with a manual override (System Default / Light / Dark) in Settings; switches instantly without restarting
At-a-glance disk cards — the drive-letter badge shows small corner icons for read-only and current-TEMP-directory status; the usage bar displays its percentage and turns to a warning color (along with the free-space text) once usage crosses 90%; read-only disks collapse the usage bar into a single line showing the backing image path instead of capacity figures that never change
About dialog — accessible from the overflow menu; shows the app version and a link to the GitHub repository

Installation

Download the latest MSI from the Releases page and run it. The installer automatically installs WinFsp if it is not already present, and selects the UI language based on your Windows locale (English or Simplified Chinese).

Before repairing or uninstalling: if you have redirected your Windows user temporary directory (TEMP/TMP) to a ManagedDrive RAM disk, reset it to the Windows default first — either from inside the app using Reset to Default Temp Directory, or manually via System Properties → Advanced → Environment Variables. The installer will remind you of this during repair and uninstall.

Prerequisites

Requirement	Notes
Windows 10 / 11 (64-bit)	ARM64 is not currently tested
WinFsp 2.2.26183 (2026 Beta2)	Must be installed before running ManagedDrive. Download the installer directly: winfsp-2.2.26183.msi — do not use `winget install WinFsp.WinFsp`, as the winget package lags behind the latest release. The managed assembly `winfsp-msil.dll` is installed to `C:\Program Files (x86)\WinFsp\bin\` and is referenced by the project automatically.
.NET 10 SDK	Required to build.

Getting Started

# 1. Download and install WinFsp 2.2.26183 (2026 Beta2)
# https://github.com/winfsp/winfsp/releases/download/v2.2B2/winfsp-2.2.26183.msi

# 2. Clone the repository
git clone https://github.com/coldhighsun/ManagedDrive
cd ManagedDrive

# 3. Build
dotnet build

# 4. Run
dotnet run --project src/ManagedDrive.App -c Release

Alternatively open ManagedDrive.slnx in Visual Studio 2022+ and press F5.

Solution Structure

ManagedDrive/
├── src/
│   ├── ManagedDrive.Core/          # In-memory file system engine (WinFsp)
│   │   ├── DiskOptions.cs          #   Immutable mount configuration record
│   │   ├── FileNode.cs             #   Single file or directory node
│   │   ├── FileNodeMap.cs          #   Thread-safe path→node dictionary
│   │   ├── MemoryFileSystem.cs     #   FileSystemBase implementation (all WinFsp callbacks)
│   │   ├── RamDisk.cs              #   Mount/unmount lifecycle wrapper
│   │   ├── MountManager.cs         #   Multi-disk manager
│   │   └── DiskImageSerializer.cs  #   Binary persistence (.mdr format)
│   │
│   └── ManagedDrive.App/           # WPF desktop application
│       ├── Localization/           #   ResourceDictionary strings (en-US, zh-CN)
│       ├── Themes/                 #   AppTheme.xaml styles + light/dark color palettes, ThemeManager
│       ├── Infrastructure/         #   RelayCommand
│       ├── Models/                 #   AppConfiguration, DiskProfile
│       ├── Services/               #   SettingsStore, StartupManager, TempDirResetService
│       ├── ViewModels/             #   MainViewModel, DiskViewModel
│       ├── Views/                  #   CreateDiskDialog, SettingsDialog, ConfirmDialog, AboutDialog, TrayTooltipView
│       ├── MainWindow.xaml(.cs)    #   Main window
│       └── App.xaml(.cs)           #   Startup, tray icon, auto-mount
│
├── tests/
│   └── ManagedDrive.Tests/         # xUnit v3 unit tests (pure-managed code only)
│       ├── FileNodeTests.cs
│       ├── FileNodeMapTests.cs
│       ├── DiskImageSerializerTests.cs
│       └── WildcardMatchTests.cs
│
└── benchmarks/
    └── ManagedDrive.Benchmarks/    # BenchmarkDotNet throughput/latency benchmarks
        ├── Program.cs
        ├── DriveLetterHelper.cs             #   Picks a free mount point (D:-Z:) for the RAM disk
        ├── SequentialReadWriteBenchmarks.cs #  Sequential read/write at 4 KB and 1 MB
        ├── RandomAccessBenchmarks.cs        #  Random-seek reads and small-file high-frequency writes
        └── ConcurrentAccessBenchmarks.cs    #  Multi-threaded reads/writes to disjoint files, measuring FileNodeMap lock contention

How It Works

ManagedDrive uses WinFsp (Windows File System Proxy) to present an in-memory directory tree as a real Windows volume. WinFsp ships a signed kernel driver that acts as a bridge; all file I/O is forwarded to MemoryFileSystem, which stores data in .NET byte arrays.

Key classes:

FileNode — holds Fsp.Interop.FileInfo metadata, a byte[] data buffer, a cached leaf name, and a security descriptor.
FileNodeMap — a case-insensitive SortedDictionary<string, FileNode> that maps full paths to nodes, supports paginated child enumeration via a bounded prefix walk, and tracks total allocated bytes with an incrementally-maintained counter (O(1) reads instead of a full scan). Thread-safe via the C# 13 Lock type.
MemoryFileSystem : FileSystemBase — overrides all 21 required WinFsp callbacks (Create, Open, Read, Write, Rename, CanDelete, ReadDirectoryEntry, etc.) and enforces a configurable capacity ceiling, returning STATUS_DISK_FULL when exceeded; memory is not pre-allocated — each FileNode holds only the bytes actually written.
RamDisk — composes MemoryFileSystem with a FileSystemHost. The static Create() factory mounts the volume and polls until the drive letter is visible in the OS (up to 2.5 s), then broadcasts SHCNE_DRIVEADD to refresh Explorer. Dispose() unmounts. When an auto-save interval is configured, a background timer saves the image immediately and then on every interval, skipping ticks where nothing has changed since the last save; a final save (always performed, regardless of changes) runs on Dispose() so unmounting, remounting, or exiting never skips the latest save.
MountManager — thread-safe registry of active RamDisk instances. Fires DiskMounted / DiskUnmounted events.
DiskImageSerializer — reads/writes .mdr files (full FS state including metadata, ACLs, and file data), optionally gzip-compressed at a user-selectable level.

Disk Image Format (`.mdr`)

A little-endian binary format:

Field	Type	Description
Magic	`byte[4]`	`MDRD`
Version	`int32`	Currently `2`
CompressionLevel	`byte`	`ImageCompressionLevel` value (0=None/1=Fastest/2=Optimal/3=SmallestSize); when not `None`, everything below is gzip-compressed
Capacity	`uint64`	Configured capacity in bytes
VolumeLabel	`string`	Length-prefixed UTF-8
NodeCount	`int32`	Number of nodes that follow
Node entries	—	Path, metadata (10 fields), security descriptor, file data

Version 1 images (no CompressionLevel byte, always uncompressed) remain readable for backward compatibility.

Settings & Persistence

Settings are stored as JSON at %APPDATA%\ManagedDrive\settings.json.
Windows startup registration uses HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run (no elevation required).
Version is derived from git tags (v-prefixed, e.g. v0.1.0) via MinVer.

Performance

Read/write, random-access, and small-file throughput measured with BenchmarkDotNet on:


CPU	Intel Core i9-13980HX, 24C/32T, 2.2 GHz base
RAM	64 GB
Disk	KIOXIA KXG8AZNV1T02 NVMe SSD (1 TB)
OS	Windows 11 Pro (Build 26200)
Runtime	.NET 10.0.9 · BenchmarkDotNet 0.15.8

SequentialReadWriteBenchmarks creates or reads a single file via FileStream at 4 KB and 1 MB. Writes use FileOptions.WriteThrough (no OS write-back cache) and reads use FileOptions.SequentialScan.

File Size	Operation	RAM Disk	NVMe SSD	Ratio
4 KB	Write	1.5 MB/s	0.8 MB/s	1.9× faster
4 KB	Read	2.2 MB/s	4.5 MB/s	0.5× slower
1 MB	Write	279 MB/s	85 MB/s	3.3× faster
1 MB	Read	547 MB/s	1,139 MB/s	0.5× slower

Why are RAM disk reads slower?
Physical disk reads appear fast because the OS page cache keeps recently-written files in DRAM. The RAM disk reads go through WinFsp's kernel–userspace bridge, which adds IPC overhead compared to the direct page-cache path. In workloads where data is written once and read many times from cold cache (e.g. build outputs, temp files that outlive page-cache pressure), the RAM disk will consistently outperform SSD on reads too.

4 KB note: small-file results are dominated by file-open/close syscall overhead, not transfer speed.

Raw latency (mean, [SimpleJob(warmupCount: 2, iterationCount: 3)]):

File Size	RamDisk Write	RamDisk Read	NVMe Write	NVMe Read
4 KB	2,582 μs	1,785 μs	4,988 μs	871 μs
1 MB	3,580 μs	1,829 μs	11,740 μs	878 μs

RandomAccessBenchmarks covers seek-heavy and small-file-heavy patterns not exercised by the sequential benchmarks above:

Scenario	RAM Disk	NVMe SSD	Ratio
Random 4 KB read (30 seeks over a 16 MB file)	3.26 ms	1.00 ms	3.3× slower
30× small-file (4 KB) create+write	75.5 ms (2.52 ms/file)	115.1 ms (3.84 ms/file)	1.5× faster

Random reads are slower on the RAM disk for the same reason sequential reads are (WinFsp kernel–userspace round-trip per I/O), while small-file writes are faster because RAM disk file creation skips physical block allocation and journaling entirely — at the cost of far higher managed memory allocation per operation (see Alloc Ratio in the raw BenchmarkDotNet output).

Running Tests

dotnet test tests/ManagedDrive.Tests

Tests cover FileNode (allocation unit alignment, index numbers), FileNodeMap (CRUD, case-insensitive lookup, child pagination, rename, capacity tracking), DiskImageSerializer (save/load round-trips across every compression level, legacy version-1 images, concurrent map mutation during save), and the wildcard glob matcher used by directory listing. Mount/unmount integration tests require the WinFsp driver and must be run manually.

Running Benchmarks

WinFsp must be installed. The benchmark project auto-selects the first free drive letter between D: and Z: — no manual configuration needed.

dotnet run --project benchmarks/ManagedDrive.Benchmarks -c Release

BenchmarkDotNet will prompt you to pick which benchmark class(es) to run (SequentialReadWriteBenchmarks, RandomAccessBenchmarks, ConcurrentAccessBenchmarks, or any combination). Results are written to BenchmarkDotNet.Artifacts/results/ in the working directory.

Known Issues

Certain installers may fail when TEMP is set to a RAM disk

WinFsp mounts drives in the current user's session device namespace. If an installer is extracted to TEMP and then launched by a system-level process — such as the Windows Package Manager service used by winget — that process operates in the global device namespace and cannot resolve user-session drive letters. Attempting to execute such an installer from a path like Z:\Temp\WinGet\...\setup.exe fails with:

0x800704b3 — The network path was not found

Known affected packages include WeChatWin_*.exe (WeChat installer), 7z*.exe (7-Zip installer), and Git-*.exe (Git installer). Not all winget packages are affected — many install without issue.

This is an architectural limitation of WinFsp user-mode file systems and cannot be worked around in user space.

Recommendation: If you encounter installation errors, you have two options:

Restore TEMP to the Windows default using the toolbar button in ManagedDrive, then retry the installation.
Download the installer directly from the software's official website and run it manually, bypassing winget entirely.

ManagedDrive will warn you when you attempt to set a RAM disk as TEMP. On every subsequent startup, if TEMP still points to a RAM disk, a warning is shown again — reset TEMP to the Windows default to stop the recurring prompt.

License

MIT

中文

基于 .NET 10 和 WinFsp 构建的 Windows RAM 虚拟磁盘管理器。
创建、挂载并管理内存盘，它们在文件资源管理器中以普通驱动器号的形式呈现。

功能特性

同时挂载多个 RAM 磁盘，每个磁盘拥有独立的驱动器号
可配置容量、卷标和只读标志
动态内存分配——磁盘容量为上限而非预分配；内存随文件写入而占用，随文件删除而释放
编辑已挂载磁盘——修改卷标、容量、自动挂载和镜像路径无需重挂即可实时生效；更改盘符或只读标志时自动重挂
可选持久化——将磁盘内容保存为 .mdr 镜像文件，下次挂载时自动还原；保存镜像功能始终可用，未设置镜像路径时自动弹出选择对话框；保存期间磁盘卡片会显示"正在保存..."提示
可选自动保存——每 1-60 分钟（创建或编辑磁盘时可配置）自动将磁盘内容保存到镜像文件；开启自动保存时会立即触发一次保存，卸载磁盘或退出应用前也会再保存一次，避免在两次定时保存之间丢失数据。若自上次保存后内容未发生变化，定时保存会自动跳过，避免不必要的磁盘 IO。镜像文件只能通过文件选择对话框设置（不可手动输入），且不能位于内存盘上，也不能与其他磁盘共用同一个镜像文件。勾选只读，或清空已选择的镜像文件，都会取消勾选并禁用自动保存（勾选只读还会同时禁用镜像压缩）——只读磁盘的内容不会变化，因此无需保存或压缩，一个没有内容的只读空盘也没有意义，而没有镜像文件时自动保存也无处可保存。磁盘卡片会显示磁盘内容最近一次被修改的时间
可选镜像压缩——为保存的 .mdr 镜像选择压缩级别（不压缩／快速／均衡／最高），在保存/加载速度与文件大小之间取舍；默认快速
应用启动时自动挂载已保存的磁盘配置
双击磁盘卡片可在资源管理器中打开对应盘符；右键菜单提供在资源管理器中打开和打开镜像文件目录（打开磁盘 .mdr 镜像文件所在的文件夹；若磁盘未配置镜像文件则该菜单项置灰不可点）
系统托盘图标，关闭窗口时最小化到托盘
托盘图标悬浮提示——鼠标悬停时显示所有已挂载磁盘及其实时使用率
高用量警告——磁盘使用率超过 90% 时通过系统托盘发出通知
可选最小化启动——直接启动到托盘，不显示主窗口
临时目录重定向——右键单击磁盘可将其设为 Windows TEMP/TMP 目录；通过工具栏、右键菜单或托盘菜单恢复系统默认值；卸载或重挂时自动恢复为系统默认临时目录；启动时若 TEMP/TMP 指向任一内存盘配置，均会显示警告——若该磁盘未设置自动挂载，还会自动将 TEMP 恢复为系统默认值
退出确认——只要还有磁盘处于挂载状态，无论是通过工具栏按钮还是托盘菜单退出，程序都会将主窗口带到前台并要求用户确认；若 TEMP/TMP 恰好指向某个已挂载的内存盘，确认提示中还会额外警告将重置 TEMP，用户确认后先重置再退出——系统发送关闭信号时不触发此流程
NTFS 兼容卷标识——内存盘以 NTFS 文件系统类型上报，可作为需要 NTFS 卷的工具（如 WinGet、Windows Update 暂存、BITS 下载）的目标路径
磁盘格式化——右键单击磁盘并选择格式化可立即删除所有文件和文件夹（只读磁盘受保护）；右键菜单按导航、配置、破坏性操作三个分组排列
系统托盘菜单——在显示、新建磁盘、退出之外，新增重置临时文件夹（静默执行，结果通过气泡通知反馈）和设置快捷入口
主窗口启动时居中显示于主屏幕并置于前台
双语界面——中文与英文，根据系统语言自动切换，也可在设置中手动更改
浅色/深色主题——默认跟随 Windows 系统主题，也可在设置中手动切换（跟随系统／浅色／深色），切换即时生效，无需重启
一目了然的磁盘卡片——驱动器字母徽章上会叠加只读、当前临时目录等状态角标；用量进度条旁显示百分比，使用率超过 90% 时进度条及可用空间文字会变为警示色；只读磁盘的用量区域会替换为单行文字，显示其绑定的镜像文件路径，而非无意义的容量数字
关于对话框——可从溢出菜单打开，显示应用版本及 GitHub 仓库链接

安装

从 Releases 页面下载最新的 MSI 安装包并运行。安装程序会在 WinFsp 未安装时自动安装，并根据 Windows 系统语言自动选择界面语言（中文或英文）。

修复或卸载前请注意： 如果您已将 Windows 用户临时目录（TEMP/TMP）重定向到 ManagedDrive 内存盘，请先将其恢复为系统默认值——在应用内使用恢复默认用户临时文件夹功能，或手动在「系统属性」→「高级」→「环境变量」中修改。安装程序在执行修复和卸载时会提示您完成此操作。

环境要求

要求	说明
Windows 10 / 11（64 位）	暂未测试 ARM64
WinFsp 2.2.26183（2026 Beta2）	必须安装此版本才能运行 ManagedDrive。请直接下载安装包：winfsp-2.2.26183.msi——不要使用 `winget install WinFsp.WinFsp` 安装，因为该 winget 包更新不及时，落后于最新发布版本。托管程序集 `winfsp-msil.dll` 将安装至 `C:\Program Files (x86)\WinFsp\bin\`，项目会自动引用。
.NET 10 SDK	编译所需。

快速开始

# 1. 下载并安装 WinFsp 2.2.26183（2026 Beta2）
# https://github.com/winfsp/winfsp/releases/download/v2.2B2/winfsp-2.2.26183.msi

# 2. 克隆仓库
git clone https://github.com/coldhighsun/ManagedDrive
cd ManagedDrive

# 3. 编译
dotnet build

# 4. 运行
dotnet run --project src/ManagedDrive.App -c Release

或者在 Visual Studio 2022+ 中打开 ManagedDrive.slnx 并按 F5。

解决方案结构

ManagedDrive/
├── src/
│   ├── ManagedDrive.Core/          # 内存文件系统引擎（WinFsp）
│   │   ├── DiskOptions.cs          #   不可变挂载配置记录
│   │   ├── FileNode.cs             #   单个文件或目录节点
│   │   ├── FileNodeMap.cs          #   线程安全的路径→节点字典
│   │   ├── MemoryFileSystem.cs     #   FileSystemBase 实现（所有 WinFsp 回调）
│   │   ├── RamDisk.cs              #   挂载/卸载生命周期封装
│   │   ├── MountManager.cs         #   多磁盘管理器
│   │   └── DiskImageSerializer.cs  #   二进制持久化（.mdr 格式）
│   │
│   └── ManagedDrive.App/           # WPF 桌面应用程序
│       ├── Localization/           #   ResourceDictionary 字符串（en-US、zh-CN）
│       ├── Themes/                 #   AppTheme.xaml 样式 + 浅色/深色配色字典、ThemeManager
│       ├── Infrastructure/         #   RelayCommand
│       ├── Models/                 #   AppConfiguration、DiskProfile
│       ├── Services/               #   SettingsStore、StartupManager、TempDirResetService
│       ├── ViewModels/             #   MainViewModel、DiskViewModel
│       ├── Views/                  #   CreateDiskDialog、SettingsDialog、ConfirmDialog、AboutDialog、TrayTooltipView
│       ├── MainWindow.xaml(.cs)    #   主窗口
│       └── App.xaml(.cs)           #   启动、托盘图标、自动挂载
│
├── tests/
│   └── ManagedDrive.Tests/         # xUnit v3 单元测试（仅纯托管代码）
│       ├── FileNodeTests.cs
│       ├── FileNodeMapTests.cs
│       ├── DiskImageSerializerTests.cs
│       └── WildcardMatchTests.cs
│
└── benchmarks/
    └── ManagedDrive.Benchmarks/    # BenchmarkDotNet 吞吐量/延迟基准测试
        ├── Program.cs
        ├── DriveLetterHelper.cs             #   为内存盘自动选择一个空闲盘符（D:-Z:）
        ├── SequentialReadWriteBenchmarks.cs #  4 KB / 1 MB 顺序读写
        ├── RandomAccessBenchmarks.cs        #  随机寻址读取 + 小文件高频写入
        └── ConcurrentAccessBenchmarks.cs    #  多线程并发读写互不重叠的文件，测量 FileNodeMap 锁竞争

工作原理

ManagedDrive 使用 WinFsp（Windows 文件系统代理）将内存目录树呈现为真实的 Windows 卷。WinFsp 附带一个已签名的内核驱动程序作为桥接层；所有文件 I/O 均转发至 MemoryFileSystem，后者将数据存储在 .NET 字节数组中。

核心类：

FileNode — 持有 Fsp.Interop.FileInfo 元数据、byte[] 数据缓冲区、缓存的叶子节点名称及安全描述符。
FileNodeMap — 不区分大小写的 SortedDictionary<string, FileNode>，将完整路径映射到节点，通过有界前缀遍历支持分页子节点枚举，并通过增量维护的计数器追踪已分配字节总量（O(1) 读取，无需全量扫描）。通过 C# 13 Lock 类型保证线程安全。
MemoryFileSystem : FileSystemBase — 覆写全部 21 个所需的 WinFsp 回调（Create、Open、Read、Write、Rename、CanDelete、ReadDirectoryEntry 等），并强制执行可配置的容量上限，超出时返回 STATUS_DISK_FULL；内存不预分配——每个 FileNode 仅保留实际写入的字节数。
RamDisk — 组合 MemoryFileSystem 与 FileSystemHost。静态工厂方法 Create() 挂载卷，并轮询直至驱动器号在系统中可见（最长 2.5 秒），随后向资源管理器广播 SHCNE_DRIVEADD。Dispose() 执行卸载。配置了自动保存间隔时，后台计时器会立即保存一次镜像，随后按间隔重复保存，若自上次保存后内容未变化则跳过该次保存；Dispose() 还会执行一次收尾保存（不受内容是否变化影响，始终执行），确保卸载、重新挂载或退出应用时不会遗漏最新的改动。
MountManager — 线程安全的活动 RamDisk 实例注册表，提供 DiskMounted / DiskUnmounted 事件。
DiskImageSerializer — 读写 .mdr 文件（保存完整文件系统状态，包含元数据、ACL 和文件数据），可选按用户指定的级别进行 gzip 压缩。

磁盘镜像格式（`.mdr`）

小端序二进制格式：

字段	类型	说明
魔数	`byte[4]`	`MDRD`
版本	`int32`	当前为 `2`
压缩级别	`byte`	`ImageCompressionLevel` 取值（0=不压缩/1=快速/2=均衡/3=最高）；非 0 时，后续内容整体经 gzip 压缩
容量	`uint64`	配置的容量（字节）
卷标	`string`	长度前缀 UTF-8
节点数	`int32`	后续节点数量
节点条目	—	路径、元数据（10 个字段）、安全描述符、文件数据

版本 1 的镜像（不含压缩级别字段，始终不压缩）仍可正常读取，保持向后兼容。

配置与持久化

配置以 JSON 格式存储于 %APPDATA%\ManagedDrive\settings.json。
开机自启通过 HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run 注册表项实现（无需提升权限）。
版本号由 MinVer 从 git 标签派生（v 前缀，例如 v0.1.0）。

性能基准

使用 BenchmarkDotNet 测量读写、随机访问及小文件吞吐量，测试环境：


CPU	Intel Core i9-13980HX，24C/32T，基础频率 2.2 GHz
内存	64 GB
磁盘	KIOXIA KXG8AZNV1T02 NVMe SSD（1 TB）
系统	Windows 11 Pro（Build 26200）
运行时	.NET 10.0.9 · BenchmarkDotNet 0.15.8

SequentialReadWriteBenchmarks 通过 FileStream 在 4 KB 和 1 MB 大小下对单个文件进行创建或读取操作。写入使用 FileOptions.WriteThrough（禁用操作系统写回缓存），读取使用 FileOptions.SequentialScan。

文件大小	操作	内存盘	NVMe SSD	倍率
4 KB	写入	1.5 MB/s	0.8 MB/s	快 1.9×
4 KB	读取	2.2 MB/s	4.5 MB/s	慢 0.5×
1 MB	写入	279 MB/s	85 MB/s	快 3.3×
1 MB	读取	547 MB/s	1,139 MB/s	慢 0.5×

为何内存盘读取反而更慢？
物理磁盘的读取速度之所以快，是因为操作系统页面缓存将最近写入的文件保留在 DRAM 中。内存盘的读取则需要经过 WinFsp 的内核–用户态桥接，引入了额外的 IPC 开销，比直接走页面缓存路径更慢。在数据写入一次、多次读取且页面缓存已失效的场景下（如构建产物、临时文件），内存盘的读取性能同样会超越 SSD。

4 KB 说明： 小文件结果主要受文件打开/关闭的系统调用开销主导，不反映实际传输速率。

原始延迟（均值，[SimpleJob(warmupCount: 2, iterationCount: 3)]）：

文件大小	内存盘写入	内存盘读取	NVMe 写入	NVMe 读取
4 KB	2,582 μs	1,785 μs	4,988 μs	871 μs
1 MB	3,580 μs	1,829 μs	11,740 μs	878 μs

RandomAccessBenchmarks 补充了顺序读写未覆盖的寻址密集与小文件密集场景：

场景	内存盘	NVMe SSD	倍率
随机 4 KB 读取（对 16 MB 文件随机寻址 30 次）	3.26 ms	1.00 ms	慢 3.3×
30 次小文件（4 KB）创建+写入	75.5 ms（2.52 ms/文件）	115.1 ms（3.84 ms/文件）	快 1.5×

随机读取在内存盘上更慢，原因与顺序读取相同（每次 I/O 都要经过 WinFsp 内核–用户态往返）；而小文件写入更快，是因为内存盘创建文件完全跳过了物理块分配和日志记录——代价是每次操作的托管内存分配量显著更高（详见原始 BenchmarkDotNet 输出中的 Alloc Ratio）。

运行测试

dotnet test tests/ManagedDrive.Tests

测试覆盖 FileNode（分配单元对齐、索引编号）、FileNodeMap（增删改查、大小写无关查找、子节点分页、重命名、容量追踪）、DiskImageSerializer（各压缩级别的保存/加载往返、旧版本 1 镜像、保存期间并发修改磁盘节点）以及目录枚举所用的通配符匹配逻辑。挂载/卸载集成测试需要 WinFsp 驱动程序，须手动运行。

运行基准测试

须已安装 WinFsp。基准测试项目会自动选择 D: 到 Z: 之间第一个空闲盘符，无需手动配置。

dotnet run --project benchmarks/ManagedDrive.Benchmarks -c Release

BenchmarkDotNet 会提示你选择要运行的基准测试类（SequentialReadWriteBenchmarks、RandomAccessBenchmarks、ConcurrentAccessBenchmarks，或任意组合）。结果将写入工作目录下的 BenchmarkDotNet.Artifacts/results/。

已知问题

将 TEMP 设为内存盘后，某些安装包可能报错

WinFsp 将驱动器挂载在当前用户的会话设备命名空间中。若安装包被解压到 TEMP 后由系统级进程启动（例如 winget 所使用的 Windows 软件包管理器服务），该进程运行于全局设备命名空间，无法解析用户会话级别的驱动器号。尝试从 Z:\Temp\WinGet\...\setup.exe 之类的路径执行安装程序时，会报错：

0x800704b3 — 网络路径键入不正确 / The network path was not found

已知受影响的安装包包括 WeChatWin_*.exe（微信安装程序）、7z*.exe（7-Zip 安装程序）和 Git-*.exe（Git 安装程序）。并非所有 winget 包都受影响——大多数包可正常安装。

这是 WinFsp 用户态文件系统的架构性限制，无法在用户空间层面绕过。

建议： 如遇安装报错，可采用以下任一方式解决：

通过 ManagedDrive 工具栏的按钮将 TEMP 恢复为 Windows 默认值，再重试安装。
直接前往软件官网下载安装包手动安装，绕过 winget。

每次将内存盘设置为临时目录时，ManagedDrive 均会弹出警告提示。此后每次启动，只要 TEMP 仍指向内存盘，警告便会再次弹出——将 TEMP 恢复为 Windows 默认值后即可停止重复提示。

许可证

MIT

Name		Name	Last commit message	Last commit date
Latest commit History 45 Commits
.github/workflows		.github/workflows
benchmarks/ManagedDrive.Benchmarks		benchmarks/ManagedDrive.Benchmarks
installer		installer
src		src
tests/ManagedDrive.Tests		tests/ManagedDrive.Tests
.gitignore		.gitignore
CLAUDE.md		CLAUDE.md
Directory.Build.props		Directory.Build.props
Directory.Packages.props		Directory.Packages.props
LICENSE		LICENSE
ManagedDrive.slnx		ManagedDrive.slnx
README.md		README.md
global.json		global.json
nuget.config		nuget.config

Folders and files

Latest commit

History

Repository files navigation

ManagedDrive

English

Features

Installation

Prerequisites

Getting Started

Solution Structure

How It Works

Disk Image Format (.mdr)

Settings & Persistence

Performance

Running Tests

Running Benchmarks

Known Issues

Certain installers may fail when TEMP is set to a RAM disk

License

中文

功能特性

安装

环境要求

快速开始

解决方案结构

工作原理

磁盘镜像格式（.mdr）

配置与持久化

性能基准

运行测试

运行基准测试

已知问题

将 TEMP 设为内存盘后，某些安装包可能报错

许可证

About

Topics

Resources

License

Uh oh!

Stars

Watchers

Forks

Releases 2

Uh oh!

Contributors

Uh oh!

Languages

Disk Image Format (`.mdr`)

磁盘镜像格式（`.mdr`）