Overview

ExtendFS is a read-only ext2, ext3, and ext4 driver for macOS using FSKit and written in Swift. It's plug-and-play, with no kernel extension or messing with system security settings required.

ext4 is one of the most common filesystem formats used by HDDs, SSDs, and USB flash drives formatted on Linux, such as by Ubuntu users. However, ext4 isn't supported by default on macOS and results in an error when you plug one of these devices into your Mac. If you want to read files off a supported Linux disk but see this error, ExtendFS can help you access them.

• Easy to Enable
  There's no need to reboot into recovery mode, lower your system security settings, or enable any kernel extensions. You just turn on a switch in System Settings.

• Easy to Use
  When opening a disk image or plugging in a drive formatted as ext4 with supported options, the volume automatically mounts and is accessible in the Finder, with no terminal commands required.

• FSKit
  Instead of FUSE implementations like macFUSE or FUSE-T, ExtendFS makes use of Apple's new FSKit framework, allowing the filesystem to be implemented in user space, increasing safety and eliminating the need for a kernel extension or other third-party downloads.

• Open Source
  The source code is freely accessible on GitHub under the GPL license. If you want to support the project, you can purchase the Mac App Store version, which has no differences.

Please note that not all ext4 features are currently supported. This includes compression and encryption. In addition, LVM is not currently supported. See the GitHub for detailed information about supported features and other limitations.

Usage

1. Download and run the ExtendFS app.

2. Enable ExtendFS's file system extension in System Settings.

   

Then, once you plug in your ext4-formatted drive or open your disk image, supported volumes will mount automatically, with no command line tools or manual mounting required.

If you do wish to use a command line tool, ExtendFS (like other FSKit extensions) integrates with the system's familiar tools, like the mount(8) command: