dracut_archlinux.md

Using dracut as default on archlinux instead of mkinitcpio ? Here a simple guide.

PS : you can check it on archwiki actually.

Installation.

Assumming you still don't have dracut and mkinitcpio, you can install dracut using pacman.

# pacman -S dracut (other packages blablabla)

Scripts for removing and installing vmlinuz and initramfs.

We need to make 2 scripts for removing and installing vmlinuz and initramfs when kernel upgrade is available. We can place them under /usr/local/bin and call them as dracut-install.sh and dracut-remove.sh.

• dracut install.sh (for installing vmlinuz and generate initramfs).

  #!/usr/bin/env bash
  
  args=('--force' '--no-hostonly-cmdline')
  
  while read -r line; do
  	if [[ "$line" == 'usr/lib/modules/'+([^/])'/pkgbase' ]]; then
  		read -r pkgbase < "/${line}"
  		kver="${line#'usr/lib/modules/'}"
  		kver="${kver%'/pkgbase'}"
  
  		install -Dm0644 "/${line%'/pkgbase'}/vmlinuz" "/boot/vmlinuz-${pkgbase}"
  		dracut "${args[@]}" --hostonly "/boot/initramfs-${pkgbase}.img" --kver "$kver"
  		dracut "${args[@]}" --no-hostonly "/boot/initramfs-${pkgbase}-fallback.img" --kver "$kver"
  	fi
  done
  

• dracut-remove.sh (for removing vmlinuz and initramfs).

  #!/usr/bin/env bash
  
  while read -r line; do
  	if [[ "$line" == 'usr/lib/modules/'+([^/])'/pkgbase' ]]; then
  		read -r pkgbase < "/${line}"
  		rm -f "/boot/vmlinuz-${pkgbase}" "/boot/initramfs-${pkgbase}.img" "/boot/initramfs-${pkgbase}-fallback.img"
  	fi
  done
  

We should not forget to set their permission to rwxr-xr-x. We can do it by using chmod command :

# chmod 755 /usr/local/bin/dracut-install.sh
# chmod 755 /usr/local/bin/dracut-remove.sh

Pacman hooks for dracut.

We need to make two hooks so pacman will automatically run the previous scripts (dracut-install.sh and dracut-remove.sh) when kernel upgrade is available. We can call them as 90-dracut-install.hook and 60-dracut-remove.hook. We can place them under /etc/pacman.d/hooks/.

• 90-dracut-install.hook

  [Trigger]
  Type = Path
  Operation = Install
  Operation = Upgrade
  Target = usr/lib/modules/*/pkgbase
  
  [Action]
  Description = Updating linux initcpios (with dracut!)...
  When = PostTransaction
  Exec = /usr/local/bin/dracut-install.sh
  Depends = dracut
  NeedsTargets
  

• 60-dracut-remove.hook

  [Trigger]
  Type = Path
  Operation = Remove
  Target = usr/lib/modules/*/pkgbase
  
  [Action]
  Description = Removing linux initcpios...
  When = PreTransaction
  Exec = /usr/local/bin/dracut-remove.sh
  NeedsTargets