Mount ext2, ext3, ext4 and Btrfs volumes on Windows, LUKS-encrypted ones included, with drive letters, in one small program.
NixMount is a Rust reimplementation of two long-running projects, Ext4Fsd and WinBtrfs, combined into a single application. Both are kernel drivers written in C. NixMount does the same job in memory-safe user-mode code, so a bug or a corrupted disk can fail one request but can't crash Windows.
| Ext4Fsd + WinBtrfs | NixMount | |
|---|---|---|
| Install | Separate installers per project | One 4 MB file, nothing else to download |
| Runs as | Two kernel drivers | One program, using the Microsoft-signed WinFsp driver it carries |
| Bad data on disk | Can crash the machine | An error on that request |
| ext4 writes | Not journaled | Journaled through the real jbd2 log |
| Mounting read-only | May replay the journal to disk | Never writes: recovery happens in memory |
| Encrypted (LUKS) volumes | Not supported | Unlocked with their passphrase |
| Secure Boot | Workarounds or a paid signature | Nothing to sign |
| Source | About 220,000 lines of C and C++, with bundled libraries | About 15,000 lines of Rust |
| Memory | Kernel pool | 5 MB for the interface, 2 MB for the idle service |
- Download
NixMount-Setup.exefrom Releases and run it. - Select Install. This is the only setup step: the driver is included.
- Pick a volume and select Mount.
Volumes mount read-only until you turn on Allow writing. To look through a volume or copy files out without installing anything, use Browse files.
Windows may warn about an unrecognized app the first time, because the file isn't code-signed. Select More info, then Run anyway.
This is a young project, and a filesystem is the last place to take that lightly. Its engines are tested hard (see Verification), but they have not yet had years of daily use. Keep backups of anything you write to, and try it on an image or a spare disk first.
- User guide: mounting, writing, snapshots, the command line, troubleshooting
- Compatibility: which filesystem features work, and what changed from the originals
- Design: how it works and how it is verified
- Security: the threat model and what the design does about it
Built by NitroDiesel and Claude. See CONTRIBUTORS.
GPL-2.0-only. See NOTICE for how this relates to the original projects.
WinFsp - Windows File System Proxy, Copyright (C) Bill Zissimopoulos, https://github.com/winfsp/winfsp