Dracut

From Arch wiki: Dracut;

dracut creates an initial image used by the kernel for preloading the block device modules (such as IDE, SCSI or RAID) which are needed to access the root filesystem. Upon installing linux, you can choose between mkinitcpio and dracut. dracut is used by Fedora, RHEL, Gentoo, and Debian, among others. Arch uses mkinitcpio by default.

• Github: dracut-ng/dracut-ng
  • Old project: Dracut Github
  • Dracut wiki
• Dracut man page
• Dracut kernel cmdline man page
• Dracut HostOnly explanation

Config

• /etc/dracut.conf
• /etc/dracut.conf.d/*

Modules

• Arch wiki: Dracut modules
• Dracut docs: Modules

Module depenencies:

• systemd-cryptsetup depends on module fido2
• shell-interpreter depends on module bash

Update initramfs images

reinstall-kernels script

Update all initramfs images using the reinstall-kernels script from the kernel-install-for-dracut package:

sudo /usr/bin/reinstall-kernels

Manually

dracut --hostonly --no-hostonly-cmdline /efi/initramfs-6.1-x86_64-dracut.img
dracut /efi/initramfs-6.1-x86_64-dracut-fallback.img

Regenerate all images, but doesn't apply host-only to the main image, which bloats it up:

sudo dracut --regenerate-all --force

Migrate from grub/mkinitcpio to sd-boot/dracut

see ./systemd-boot-migration.md

Inspect image

Show all information:

sudo lsinitrd --size --kver $(uname -r)

List modules:

sudo lsinitrd --kver $(uname -r) -m