Arch Linux Install with BTRFS, LUKS, and systemd-boot, dual-booted with a UKI and Windows 11 on a shared EFI partition

archinstall.md

Arch Linux Install with BTRFS, LUKS, and systemd-boot, dual-booted with a UKI and Windows 11 on a shared EFI partition

By Raymo111

Last updated 2025-09-28

Disclaimer: I have personally tested the steps in this install. However, I'm not responsible for anything you do.

Pre-install

1. Boot Windows, install the latest updates, remove OEM bloatware, open Disk Management, and shrink the Windows partition to make room for Arch.
2. Download the latest Arch ISO and flash it with Etcher.
3. Control Panel > Power Options > Choose what the power buttons do > Change settings that are currently unavailable > Uncheck Fast startup.
4. regedit > HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation > Create a new DWORD, name it RealTimeIsUniversal, and set it to 1.
5. Boot gparted-live, move the last two tiny Windows partitions to the left.
6. Turn off secure boot in BIOS, reboot into the Arch ISO.

Note: the following steps (until the first reboot) should be done all in one go without unnecessary reboots (including back to Windows).

Install

1. Turn down brightness:

   echo 20 > /sys/class/backlight/<screen>/brightness
   

2. Connect to Ethernet/WiFi: iwctl > station list > station <device> scan > station <device> get-networks > station <device> connect <SSID> > Ctrl+d > ping 1.1.1.1

• If you get an error, you might need to rfkill unblock wlan and/or ip link set <device> up

3. cat /sys/firmware/efi/fw_platform_size > check that your computer is 64-bit. If it's not, this guide is not for you, you should try another guide (make sure to re-enable secure boot before booting back into Windows).
4. timedatectl > check that NTP is active, and that RTC is not in local TZ. If either are not, run timedatectl set-ntp true && timedatectl set-local-rtc true
5. fdisk -l to check your disks' and partitions' current configurations.
6. cfdisk /dev/nvme0n1 (or /dev/sda1 if using SATA rather than NVME disks) > Scroll down using arrow keys to Free Space > [New] to create a new Linux Filesystem partition > Choose your size and Press Enter. Write and quit.
7. Setup and open LUKS (replace X with the partition number of the partition you just created (e.g. 6):

   cryptsetup luksFormat /dev/nvme0n1pX
   cryptsetup open /dev/nvme0n1pX luks
   

8. Create and mount BTRFS:

   mkfs.btrfs -L arch /dev/mapper/luks
   mount /dev/mapper/luks /mnt
   

9. Create BTRFS subvolumes:

   btrfs subvolume create /mnt/@
   btrfs subvolume create /mnt/@swap
   btrfs subvolume create /mnt/@home
   btrfs subvolume create /mnt/@log
   btrfs subvolume create /mnt/@cache
   btrfs subvolume create /mnt/@scratch
   

10. Remount:

    umount /mnt
    mount -o noatime,ssd,compress=zstd,subvol=@ /dev/mapper/luks /mnt
    

11. Create mountpoints:

    mkdir -p /mnt/{boot,home,var/log,var/cache,scratch,btrfs}
    

12. Mount subvols:

    mount -o noatime,ssd,compress=zstd,subvol=@home /dev/mapper/luks /mnt/home
    mount -o noatime,ssd,compress=zstd,subvol=@log /dev/mapper/luks /mnt/var/log
    mount -o noatime,ssd,compress=zstd,subvol=@cache /dev/mapper/luks /mnt/var/cache
    mount -o noatime,ssd,compress=zstd,subvol=@scratch /dev/mapper/luks /mnt/scratch
    mount -o noatime,ssd,compress=zstd,subvolid=5 /dev/mapper/luks /mnt/btrfs  # const 5 for BTRFS's root
    

13. Mount EFI partition:

    mount /dev/nvme0n1p1 /mnt/boot
    

14. Create swapfile:

    cd /mnt/btrfs/@swap
    btrfs filesystem mkswapfile --size 20g --uuid clear ./swapfile  # replace 20 with a number slightly larger than your ram if you want to hibernate
    swapon ./swapfile
    cd
    

15. Configure mirrorlist:

    cp /etc/pacman.d/mirrorlist /etc/pacman.d/mirrorlist.bak  # backup mirrorlist
    reflector -c "CA" -f 12 -l 10 -n 12 --save /etc/pacman.d/mirrorlist  # (replace CA with your country code)
    pacman -Syy
    

• Uncomment following lines for 32-bit pkgs:

   vim /etc/pacman.conf
   ---
   [multilib]
   Include = /etc/pacman.d/mirrorlist
  

16. Install base system:

• AMD:

   pacstrap -K /mnt base base-devel linux-lts linux-firmware btrfs-progs \
   amd-ucode mesa xf86-video-amdgpu vulkan-radeon libva-mesa-driver mesa-vdpau \
   networkmanager sudo neovim git reflector
  

• Intel:

   pacstrap -K /mnt base base-devel linux-lts linux-firmware btrfs-progs \
   intel-ucode mesa xf86-video-intel vulkan-intel intel-media-driver \
   networkmanager sudo neovim git reflector
  

17. Init fstab and verify after:

    genfstab -U /mnt >> /mnt/etc/fstab
    

18. Chroot into the new system:

    arch-chroot /mnt
    

19. Set timezone:

    ln -sf /usr/share/zoneinfo/America/Toronto /etc/localtime # replace with your timezone
    hwclock --systohc --utc
    

20. Set locale: uncomment desired locales from /etc/locale.gen:

    locale-gen
    echo "LANG=en_CA.UTF-8" > /etc/locale.conf
    export LANG=en_CA.UTF-8
    

21. Set hostname:

    echo "arch" > /etc/hostname # replace with your hostname
    

22. Add hosts (replace hostname with your hostname):

    alias vim=nvim
    vim /etc/hosts
    ---
    127.0.0.1 <hostname>.localdomain localhost
    ::1 localhost.localdomain localhost
    

23. Set root password:

    passwd
    

24. Create your user:

    useradd -mG wheel,storage,power,log,adm,uucp,tss,rfkill -s /bin/bash <username> # replace with your username
    passwd <username>
    

25. Give user sudo access:

    EDITOR=nvim visudo
    ---
    # raymo ALL=(ALL:ALL) ALL # for passworded sudo
    # raymo ALL=(ALL:ALL) NOPASSWD:ALL # for passwordless sudo
    # only uncomment (remove the leading #) one of the two above, replace raymo with your username
    

26. Enable NetworkManager:

    systemctl enable NetworkManager
    

27. mkinitcpio:

    vim /etc/mkinitcpio.conf
    ---
    HOOKS=(base keyboard systemd autodetect modconf kms block keymap sd-vconsole sd-encrypt btrfs filesystems fsck)
    

28. Configure kernel parameters:

    vim /etc/kernel/cmdline
    ---
    root=/dev/mapper/luks rootflags=subvol=@,x-system.device-timeout=30 rw quiet splash bgrt_disable resume=/dev/mapper/luks resume_offset=<offset>
    

• Get offset from:

   btrfs inspect-internal map-swapfile -r /btrfs/@swap/swapfile
  

29. Create crypttab:

    vim /etc/crypttab.initramfs
    ---
    luks           UUID=<uuid>    -                       discard,tpm2-device=auto
    

• Get UUID from:

   blkid /dev/nvme0n1pX
  

30. Configure .preset:

    vim /etc/mkinitcpio.d/linux-lts.preset
    

• Uncomment the default_uki= lines, replace any /efi/* with /boot/*, comment out the default_image= line, uncomment splash if desired, comment out fallback lines, remove 'fallback' from the PRESETS line
• Make sure /boot/EFI/Linux exists (where uki points to). If it doesn't, mkdir -p /boot/EFI/Linux.

31. Install systemd-boot:

    chmod 700 /boot
    bootctl --path=/boot install
    chmod 700 /boot/loader/random-seed
    

32. mkinitcpio -P
33. Install userspace apps:

    pacman -S plasma kde-applications
    

34. Enable sddm:

    systemctl enable sddm
    

35. Configure make:

    vim /etc/makepkg.conf
    ---
    MAKEFLAGS="-j$(nproc --ignore=2)" # 2 less than total threads
    

36. Install yay:

    sudo -su <username>
    git clone https://aur.archlinux.org/yay.git
    cd yay
    makepkg -si
    exit
    

37. Exit chroot, unmount, shutdown:

    exit
    umount -R /mnt
    shutdown now
    

• If you get the target is busy error during umount, check what's going on with:

   fuser -m /mnt
  

38. Configure BIOS boot order. Set Linux as first boot option because systemd-boot will auto-detect Windows and add it to the boot menu.
39. Boot into Arch and pat yourself on the back.
40. Enroll TPM so you don't have to keep typing in your LUKS password:

    sudo systemd-cryptenroll --tpm2-device=<path> --tpm2-pcrs=7 /dev/nvme0n1pX
    

• Get path from:

   sudo systemd-cryptenroll --tpm2-device=list
  

41. Install UKI pacman hook to trigger rebuild after ucode update:

    sudo mkdir -p /etc/pacman.d/hooks/
    sudo nvim /etc/pacman.d/hooks/ucode.hook
    ---
    [Trigger]
    Operation=Install
    Operation=Upgrade
    Operation=Remove
    Type=Package
    # Change to appropriate microcode package
    Target=amd-ucode
    # Change the linux part above and in the Exec line if a different kernel is used
    Target=linux
    
    [Action]
    Description=Update Microcode module in initcpio
    Depends=mkinitcpio
    When=PostTransaction
    NeedsTargets
    Exec=/bin/sh -c 'while read -r trg; do case $trg in linux) exit 0; esac; done; /usr/bin/mkinitcpio -P'
    

42. Install sbctl and efitools:

    yay -S sbctl efitools
    

43. Backup your existing keys:

    for var in PK KEK db dbx ; do efi-readvar -v $var -o old_${var}.esl ; done
    

44. Reboot into bios and delete the manufacturer PK/all keys. Reboot back into Arch.
45. Setup sbctl:

    sudo sbctl status
    sudo sbctl create-keys
    sudo chattr -i /sys/firmware/efi/efivars/{PK,KEK,db}*
    sudo sbctl enroll-keys -m
    sudo sbctl verify # shows you what to sign
    # e.g.
    # sudo sbctl sign -s /boot/EFI/Boot/bootx64.efi
    # sudo sbctl sign -s /boot/EFI/Linux/arch-linux-lts.efi
    # sudo sbctl sign -s /boot/EFI/systemd/systemd-bootx64.efi
    

46. Add a hook for automatically signing after upgrades:

    sudo vim /etc/initcpio/post/uki-sbctl
    ---
    #!/usr/bin/env bash
    sbctl sign-all
    ---
    sudo chmod +x /etc/initcpio/post/uki-sbctl
    

47. Setup snapper
48. Shutdown, set an admin bios password if you haven't already, and reboot.

How to fix Arch when Windows update kills your EFI partition

1. Turn off secure boot
2. Boot into an Arch liveUSB
3. Unlock luks:

   cryptsetup open /dev/nvme0n1pX luks
   

4. Mount the unlocked partition:

   mount -o noatime,ssd,compress=zstd,subvol=@ /dev/mapper/luks /mnt
   

5. Mount the EFI partition:

   mount /dev/nvme0n1p1 /mnt/boot
   

6. Chroot into the FS:

   arch-chroot /mnt
   

7. Fix your EFI partition:

   mkinitcpio -P
   

8. Turn secure boot back on.

Thank you very much, this is the setup I've been looking to use while I learn more and it worked like a charm.

Quick question. There's no microcode entry in hooks of step 27. Is this intentional? Don't know enough yet to say either way but thought this might need to be included, as the pacman trigger to rebuild involves the microcode. I included it in mine and it worked but will redo and remove if it's not necessary. EDIT: NVM, further reading tells me it's not needed.