Dracut (software)

Dracut is a set of tools that provide enhanced functionality for automating the Linux boot process. The tool named dracut is used to create a Linux boot image (initramfs) by copying tools and files from an installed system and combining it with the Dracut framework, which is usually found in /usr/lib/dracut/modules.d.

Dracut

Output of dracut regenerating initramfs
Original author(s)	Harald Hoyer and others
Initial release	July 2009; 15 years ago (2009-07)
Stable release	106 / 1 February 2025; 2 months ago (2025-02-01)
Repository	github.com/dracut-ng/dracut-ng
Written in	C, Bash, Rust
Operating system	Linux
Platform	Linux kernel
Type	Initial_ramdisk
License	GPLv2+, LGPLv2+
Website	dracut-ng.github.io

The initramfs has essentially one purpose: locating and mounting the real root file system so that the boot process can transition to it. This functionality is dependent on device availability. Therefore, instead of having hard-coded scripts to determine device availability and suitability, Dracut's initramfs depends on the Linux device manager (udev) to create symbolic links to device nodes. When the root file system's device node appears, Dracut mounts it as the new root file system. This helps to minimize the time required in initramfs such that, for example, 5-second boots are possible.^[1]

Most of the initramfs generation functionality in Dracut is provided by generator modules that are sourced by the main dracut tool to install specific functionality into the initramfs. They live in the modules subdirectory, and use functionality provided by dracut-functions to do their work.^[1]

Features

Currently, dracut supports booting from ext2, ext3, ext4, btrfs, iso, ZFS, DM RAID, MD RAID, lvm, device mapper multipath I/O, dm-crypt, CIFS, FCoE, iSCSI, NBD and NFS.

Dracut can be used for live media generation. It has flags for squashfs, and other things like overlay file system.^[1]

History

Dracut originated from Fedora Linux sponsored initially by Red Hat in Dec 2008 ^[2]. Dracut is named after the town of Dracut, similar to Wayland and Weston. This follows the tradition of Red Hat naming projects after places near the headquarters of Red Hat in Westford, Massachusetts.^[3]

In 2013, the development moved to GitHub from Kernel.org, while a mirror was maintained till 2022 (v56).

As of Oct 2021, after the long time lead developer Harald Hoyer left Red Hat it is a community-managed open source project.

In Mar 29 2024, the project was moved to a new code repository by the core team after the project leader had not been heard from for several months.

In Feb 2025 Ubuntu announced a plan to switch the default initramfs infrastructure from initramfs-tools to dracut.

Adoption

Distributions that depend on dracut as the default initramfs tool. The list is sorted by the date when dracut became the default for a given distribution.

• Fedora Linux (2009, version 12 Constantine)^[4]
• Red Hat Enterprise Linux (2010, version 6)^[5]
• Gentoo (2010 for custom kernels^[6], 2020 for distribution kernels)^[7]
• openmamba (2010)^[8]
• OpenMandriva Lx (2011, Mandriva Linux)^[9]
• Mageia (2012, version 2)^[10]
• Void Linux (2012)^[11][12]
• Solus (operating system) (2013)
• openSUSE (2014, version 13.2)^[13]
• SUSE Linux Enterprise (2014, version 12)
• Adelie Linux (2017)^[14]
• ALT Linux (2020)^[15]
• PhotosOS (2015)
• AOSC OS (2021)
• KaOS (2021)
• EndeavourOS (2022)
• Garuda Linux (2023, Raptor)
• Azure Linux (2024)
• Ubuntu (2011, version 11.04 universe repository)^[16], (2024-Feb dracut-install in main repository, Lubuntu moved to dracut by default)^[17][18]
• Debian (2010, version 6 Squeeze)^[19], (2024-March, dracut-install)^[20]
• Chimera Linux (2024-Jun, dracut-install)
• Side Linux (2024-Sept)
• Slackware (2024-Sept)

Most distributions have made the dracut package available to allow replacing the distribution's default initramfs generator. Significant (but incomplete) list of these distributions:

• Arch Linux (2019, extra repository)^[21]
• CRUX (2021)
• Alpine Linux (2022, community repository)^[22]
• NixOS (2023)^[23]

See also