dracut (initramfs)

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dracut
Basic data

developer Harald Hoyer and many more
Current  version 048
(July 6, 2018)
operating system GNU / Linux
programming language Shell script
category Initramfs
License GPL v2 + and LGPL v2 +
German speaking No
dracut.wiki.kernel.org

dracut is software to create an initramfs - a temporary file system - for Linux systems . This is used by the Linux kernel during the boot process until the final root file system is mounted.

The aim of dracut is to offer a universal interface for creating an initramfs that can be used by all distributions. Because so far every distribution has used a self-developed procedure to generate these initramfs, which reduces usability and interoperability and increases the susceptibility to errors.

Technical characteristics

dracut has a modular structure and offers defined interfaces in order to be able to expand the functionality relatively easily.

All modules must be programmed in the scripting language of the Debian Almquist Shell (/ bin / dash), a compact operating system shell.

dracut offers special dash functions to

  • Simply embed files when creating the initramfs.
  • install required programs in initramfs (e.g. awk )
  • Check dependencies among the dracut modules.
  • Define hooks.

Hooks

Dash scripts that are called or executed when certain events occur are called hooks. These are …

  • cmdline - the evaluation of the boot parameters.
  • pre-udev - before hardware detection starts.
  • pre-mount - immediately before running the mount command.
  • mount - when the directories are mounted.
  • pre-pivot - before the initramfs is exited and the final root directory is changed.

history

In summer 2009 dracut became part of a widely used Linux distribution for the first time with Fedora 12. The project is now based directly on the Linux kernel project.

Web links

Individual evidence

  1. ^ The dracut Open Source Project on Open Hub: Languages ​​Page . In: Open Hub . (accessed October 18, 2018).
  2. ↑ lwn.net article about dracut (English)
  3. ↑ fedora-wiki