Dual-Boot Windows and Omarchy (single-drive, with LUKS Encryption)

[realbpr]

As of today, the extent the official Omarchy installation process supports dual-booting is referring to the Manual installation page in the Manual, which primarily uses archinstall. However, dual-booting this way only works by having two separate drives, because archinstall's Default Partitioning requires a complete drive for itself. Common workarounds on other guides that involve manually partitioning, then archinstall's Pre-mounted partitions option work but are unfortunately incompatible with LUKS encryption for linux on a btrfs partition (as of archinstall v4.3), which fails to find the root partition if it's encrypted. Encryption on a daily driver is must-have.

The following is a guide to dual-boot Omarchy and Windows, with Omarchy installed on a LUKS encrypted btrfs partition on the same drive as Windows. This is a fully manual installation that completely foregoes archinstall for the reasons above, and is designed to replicate what the archinstall installation does, and with the specifics given in the Manual installation page.This worked for me on a Dell G3 laptop with Windows 10.

Note: This requires Windows Secure Boot to be disabled, and only the Omarchy partition is LUKS encrypted.

Step 0: Windows and BIOS Preparations

1. Shrink Windows Partition: Create free unallocated space within Windows using Disk Management.

   • Note: Windows could be stingy about how much space it allows you to take away from it, even if C: has enormous amounts of free space. My solution was literally to just wait a few days after clearing up space. I tried again, and it allowed me to free up a significantly larger amount of disk space.

2. Disable Secure Boot: In BIOS settings, disable SecureBoot. Else it won't allow you to boot arch iso from a USB.

3. Storage Controller: If lsblk does not see your drive, reboot and go into BIOS settings and check if Storage Controller Mode is Intel RST, Intel Rapid Storage, RAID, or VMD. Arch often can't see these. This is how you change it to AHCI, which Arch will see.
   Important: You must set Windows to Safeboot before changing it to AHCI (or it won't use the right storage driver and fail to boot):

i. In Windows, open Command Prompt as Administrator and enter: bcdedit /set {current} safeboot minimal
ii. Reboot to BIOS. Change Storage Controller to to AHCI.
iii. Boot to Windows (should automatically boot in Safe Mode). Open Command Prompt as Administrator and enter:
bcdedit /deletevalue {current} safeboot
iv. Reboot normally. Windows should now work with AHCI as storage controller.

Step 1: Boot into Arch ISO

1. Flash a standard Arch ISO (not Omarchy ISO) onto your flash drive. I recommend Rufus for this.

2. Boot from the USB and wait for the root@archiso prompt.

Step 2: Connect to the Internet

If using Wi-Fi:

Bash

iwctl
station wlan0 get-networks               # See your available netwoks
station wlan0 connect your-network-name  # Prompts you for wifi password
exit

If you're plugged in via ethernet, you're already connected.

Step 2.5: (Optional) SSH Access

Recommended to have a clipboard for this, which the archiso terminal does not have.

Bash

passwd                # Create root password
systemctl start sshd  # Start SSH
ip a                  # Note your IP beside wlan0 (192.168.x.x)

From your other computer: ssh root@192.168.x.x

Step 3: Create Partitions

See your drive with lsblk. You should see your flash drive (will have same size as your USB and typically be called sda), and your main drive (typically nvme0n1 on new computers). Henceforth I will call it nvme0n1. You should also see a bunch of Windows' partitions.
Enter the cfdisk TUI for partitioning with cfdisk /dev/nvme0n1.

1. EFI Partition: Highlight your free space and select 'New'. Type in 1G as its size, then set its Type as EFI system

2. Root Partition: Highlight your free space again, select 'New', and by default should have the remaining free space as its size, so hit Enter. Make Type btrfs.

3. Write and Quit.

   Note: This guide assumes your EFI is nvme0n1p7 and Root is nvme0n1p8.

Step 4: Configure Partitions

NOTE: (replace nvme0n1p7 with your EFI partition)
Configure EFI partition: mkfs.fat -F32 /dev/nvme0n1p7

Configure omarchy partition as LUKS container (replace nvme0n1p8 with your main linux partition)

Bash

crytsetup luksFormat --type luks2 /dev/nvme0n1p8
cryptsetup open /dev/nvme0n1p8 cryptroot

Format btrfs on top of LUKS: mkfs.btrfs /dev/mapper/cryptroot

Mount your partitions (replace nvme0n1p7 with your EFI partition)
Bash

mount /dev/mapper/cryptroot /mnt
mount /dev/nvme0n1p7 /mnt/boot

Step 5: Create and Mount Subvolumes

Create btrfs subvolumes
Bash

btrfs subvolume create /mnt/@ 
btrfs subvolume create /mnt/@home 
btrfs subvolume create /mnt/@log 
btrfs subvolume create /mnt/@pkg 
btrfs subvolume create /mnt/@.snapshots
umount -R /mnt

Mount subvolumes (replace nvme0n1p7 with your EFI partition)

Bash

mount -o subvol=@,compress=zstd /dev/mapper/cryptroot /mnt 
mkdir -p /mnt/{home,var/log,var/cache/pacman/pkg,.snapshots,boot} 
mount -o subvol=@home,compress=zstd /dev/mapper/cryptroot /mnt/home
mount -o subvol=@log,compress=zstd /dev/mapper/cryptroot /mnt/var/log
mount -o subvol=@pkg,compress=zstd /dev/mapper/cryptroot /mnt/var/cache/pacman/pkg mount -o subvol=@.snapshots,compress=zstd /dev/mapper/cryptroot /mnt/.snapshots
mount /dev/nvme0n1p7 /mnt/boot

Step 6: System Provisioning

Install base system
Bash

pacstrap -K /mnt base linux linux-firmware btrfs-progs cryptsetup \
	networkmanager pipewire pipewire-pulse wireplumber \
sudo wget curl git limine efibootmgr

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

Step 7: System Configuration

Chroot in: arch-chroot /mnt

Set your timezone (replace America/Dallas with yours)
Bash

ln -sf /usr/share/zoneinfo/America/Dallas /etc/localtime
hwclock --systohc

Set your hostname (replace archlinux with your desired hostname): echo "archlinux" > /etc/hostname

Set root password: passwd

Set your locale (replace en_US with yours)
Bash

sed -i 's/#en_US.UTF-8/en_US.UTF-8/' /etc/locale.gen
locale-gen
echo "LANG=en_US.UTF-8" > /etc/locale.conf

Create superuser (replace yourusername with your desired one): useradd -m -G wheel -s /bin/bash yourusername
Create superuser's password: passwd yourusername
Make user super (i.e. sudo access): sed -i 's/# %wheel ALL=(ALL:ALL) ALL/%wheel ALL=(ALL:ALL) ALL/' /etc/sudoers

Step 8: Configure Bootloader

i. Hooks line and initcpio:
sed -i 's/^HOOKS=.*/HOOKS=(base udev autodetect microcode modconf block keyboard encrypt filesystems)/' /etc/mkinitcpio.conf

Then compile it with:
mkinitcpio -P

ii. Enable network services:
systemctl enable NetworkManager

iii. Limine bootloader (replace nvme0n1 --part7 with your EFI partition)
Bash

mkdir -p /boot/EFI/limine
cp /usr/share/limine/BOOTX64.EFI /boot/EFI/limine/

efibootmgr --create --disk /dev/nvme0n1 --part 7 \
  --label "Arch Linux" --loader '\EFI\limine\BOOTX64.EFI' --unicode

iv. See your LUKS partition's UUID (replace nvme0n1p8 with your main linux partition):
blkid -o value -s UUID /dev/nvme0n1p8

v. Create /boot/EFI/limine/limine.conf. Replace "Your-UUID-here" with the UUID you got from above.
Bash

cat > /boot/EFI/limine/limine.conf << 'EOF'
timeout: 5
/Arch Linux
	protocol: linux
	path: boot():/vmlinuz-linux cmdline: cryptdevice=UUID=Your-UUID-here:cryptroot root=/dev/mapper/cryptroot rootflags=subvol=@ rw quiet
	module_path: boot():/initramfs-linux.img
EOF

vi. Create Pacman hook (keeps Limine updated):
Bash

mkdir -p /etc/pacman.d/hooks
cat > /etc/pacman.d/hooks/99-limine.hook << 'EOF'
[Trigger]
Operation = Install
Operation = Upgrade
Type = Package
Target = limine
[Action]
Description = Deploying Limine after upgrade...
When = PostTransaction
Exec = /usr/bin/cp /usr/share/limine/BOOTX64.EFI /boot/EFI/limine/
EOF

Step 9: Reboot into Arch Linux

Bash

exit
umount -R /mnt
cryptsetup close cryptroot
reboot

Right now, Limine will only show Arch Linux. We will add Windows Boot Manager to it later because the Omarchy install overwrites limine.conf. I recommend verifying that you can still boot into Windows from your computer's BIOS menu.

Step 10: Install Omarchy

Install Omarchy with curl -fsSL https://omarchy.org/install | bash

Now when you boot up, if Windows does not show up on your Limine,

• boot into Omarchy and sudo limine-scan
  • should find Windows Boot Manager, and ask if you want to add it to Limine. Approve it.
    When you boot into Limine it should now be there.
    Optional: change Limine listing name of "Windows Boot Manager" to "Windows 10/11" with sudo nvim /boot/limine.conf

Post-Install Notes

This install should work just fine for almost everyone but due to the nature of manual install, there may be a few hardware specific things missing specific to your hardware. Only issues I encountered were audio not detecting my sound card (one-liner fix), and DNS not working (two-line fix).

Audio not working because of missing firmware. FIX: install sof-firmware from pacman and reboot.
Could have been prevented by adding sof-firmware in the pacakages named in Step 6. (Didn't include it because not for everyone.)

DNS not working (wifi not working despite saying it's connected and being able to SSH). Basically /etc/resolv.conf was invalid for some reason, so remove, then regenerate it. Still not sure why this happened for me but fix was easy.
Bash

sudo rm /etc/resolv.conf
sudo systemctl restart NetworkManager

[nightdevil00]

Omarchy uses iwd for the network stack so that was why you got the error with wifi.