Dual boot (on a single SSD)

[peregrinus879]

• Edited again on 2025-09-14 to reflect omarchi ISO & Limine bootloader chages

As 'archinstall' and 'omarchy' ISOs do not currently support "pre-mount" partitioning option with LUKS encryption, this is what I did to dual boot ArchLinux & Win11 on a single SSD.

General:
-- BIOS: Secure Boot OFF
-- Prepare GParted, ArchLinux & Win11 live usb's

Assumption:
archinstall/omarchy created 2 partitions:
-- nvme0n1p1 as boot; &
-- nvme0n1p2 as encrypted root with all the btrfs subvolumes.

Steps:
01 Boot into GParted live usb
02 Select default options
03 Select /dev/nvme0n1
04 Unlock encryption on /dev/nvme0n1p2
05 Shrink /dev/nvme0n1p2 to create unallocated space at the end (according to your Win11 space preference)
06 Lock /dev/nvme0n1p2
07 Apply changes
08 Reboot into ArchLinux live usb
09 Run "gdisk /dev/nvme0n1"
10 Create 2 partitions:
-- p3 and assign last sector as "+128M" & type as "0C01" (Windows Reserved Partition); &
-- p4 and assign type as "0700" (Microsoft Basic Data)
11 (Optional) Run "cfdisk /dev/nvme0n1" to check partition types were done correctly
12 Run "mkfs.ntfs /dev/nvme0n1p4" (this will take time)
13 Reboot into Win11 live usb
14 Select nvme0n1p4 partition and install Win11
15 Boot into BIOS and change first boot option from Windows to Limine.
16 Boot into omarchy
17 Append "/boot/limine.conf" with:
/Windows
comment: Microsoft Windows 11
comment: order-priority=20
protocol: efi_chainload
image_path: boot():/EFI/Microsoft/Boot/bootmgfw.efi
18 Reboot

For step 12, if you run the command with "-f" it will not take time but Win11 was crashing after installation. This might not be a persistent issue though.

I'm not a tech person, I just did it out of a need to run both on a single SSD. If anyone has a simpler approach, please let me know.

[Ashur-D]

This is the video I used for dual booting before fully committing to omarchy. Hopefully this is more clear and simple, he explains quite alot and even shows you how to add the windows entry to grub.

[peregrinus879]

Thanks for sharing the video. This works, except:

1. It does not use btrfs as recommended in the omarchy manual; and more importantly

2. It skips the LUKS encryption step, which is essential for omarchy, as it is designed as a single user environment. Only LUKS encryption pw is needed to log in.

Archinstall script does not allow for LUKS when using pre-mounted partitions, hence, the more complicated approach.

[Ashur-D]

Thanks for sharing the video. This works, except:

1. It does not use btrfs as recommended in the omarchy manual; and more importantly

2. It skips the LUKS encryption step, which is essential for omarchy, as it is designed as a single user environment. Only LUKS encryption pw is needed to log in.

Archinstall script does not allow for LUKS when using pre-mounted partitions, hence, the more complicated approach.

yes your right, sorry about that. Now that I think about it im pretty sure I didnt use LUKS when dual booting, but with the new update out now its recommended to have 2 separate SSD's if you want to dual boot.

[peregrinus879]

Agreed. I just put it out there as a workaround for a single SSD like in my case.

[darshfi]

Can you help me out with how did you manage to get it working on a single SSD, because I am having some issues, and I have windows installed already and want to get omarchy now without losing my data> Agreed. I just put it out there as a workaround for a single SSD like in my case.

[peregrinus879]

You will have to reinstall win after omarchy using the method in the original post. Omarchy wipes out the whole drive during installation.

[n-studio]

Here are the steps I used to install Omarchy in dual boot with Windows (inspired by https://www.youtube.com/watch?v=9jTk3K3ExaI):

1. Use iwctl to connect to wifi
2. fsdisk /dev/nvme0n1 -> make 1 EFI partition (nvme0n1p4 - 1G), 1 Linux partition (nvme0n1p5 - remaining space)
3. Format

mkfs.vfat -F 32 /dev/nvme0n1p4
mkfs.btrfs /dev/nvme0n1p5

4. Create subvolumes (not sure if optional or mandatory). Do NOT create a subvolume for snapshots, it will raise errors during archinstall.

mount /dev/nvme0n1p5 /mnt
btrfs su cr /mnt/@
btrfs su cr /mnt/@home
btrfs su cr /mnt/@pkg
btrfs su cr /mnt/@log

umount /mnt
mkdir /mnt/archinstall
mount -o noatime,compress=zstd,discard=async,space_cache=v2,subvol=@ /dev/nvme0n1p5 /mnt/archinstall

mkdir -p /mnt/archinstall/home
mkdir -p /mnt/archinstall/var/cache/pacman/pkg
mkdir -p /mnt/archinstall/var/log

mount -o noatime,compress=zstd,discard=async,space_cache=v2,subvol=@home /dev/nvme0n1p5/mnt/archinstall/home
mount -o noatime,compress=zstd,discard=async,space_cache=v2,subvol=@pkg /dev/nvme0n1p5/mnt/archinstall/var/cache/pacman/pkg
mount -o noatime,compress=zstd,discard=async,space_cache=v2,subvol=@log /dev/nvme0n1p5/mnt/archinstall/var/log

mkdir -p /mnt/archinstall/boot
mount /dev/nvme0n1p4 /mnt/archinstall/boot

5. Run archinstall following https://learn.omacom.io/2/the-omarchy-manual/96/manual-installation, except;

Disk configuration -> Pre-Mounted configuration -> /mnt/archinstall
Disk > Disk encryption > Disabled (I disabled it out of fear it could break something, but maybe it's possible to enable encryption)

6. Chroot into the newly created installation
7. Copy the Windows EFI to the new EFI

mkdir /mnt/win
mount /dev/nvme0n1p1 /mnt/win
cp -r /mnt/win/EFI/Microsoft /boot/EFI

Add to /boot/limine.conf

/Windows
comment: Microsoft Windows Boot Manager
comment: order-priority=20
protocol: efi_chainload
image_path: boot():/EFI/Microsoft/Boot/bootmgfw.efi

8. Reboot and login as user and run: curl -fsSL https://omarchy.org/install | bash

[n-studio]

How about encrypting it before running archinstall?

[peregrinus879]

Tried that as well. Pre-mount+encryption is not supported by archinstall. Will work if you install arch manually, not via archinstall, and definitely not via omarchy iso.

[johntao]

I tried this approach (as mentioned previously, this doesn't include disk encryption), it works.
However, to anyone whom may wish to try, beware that /boot/limine.conf is also editable after curl -fsSL https://omarchy.org/install | bash.
In my case, the limine.conf file generated by archinstall and Omarchy are quite different (both file location and content).
I sudo edited the file after Omarchy installation and everything looks good 😄

p.s. successfully installed the dual boot setup on 2025-09-23

[Hikarikun42]

I tried this but I got 'Invalid configuration: Boot partition not found'
How do I resolved this?

[johntao]

The boot partition is something related to step 2 “EFI partition”.

Also, Windows has its own partition if you wish to dual boot; make sure you don’t overwrite the content.

In my setup, I created a new boot partition for Linux (hence, two boot partitions total).

It is possible to use one boot partition for two OSes; however, I am not familiar with this approach. It is better to play it safe.

Please refer to ArchWiki: Partitioning for more information

[danielscc]

This was perfect for me, I was all night trying to make it work, the installing omarchy first then shrinking didn't occur to me at all lol.

Step 12 did take some time, like 1 1/2 hours but I didn't want risk it and just waited for it while I was out.

Thanks a lot!

[eososlinux]

Use iwctl to connect to wifi
ping -c 3 archlinux.org

lsblk

cfdisk /dev/sdXY

2G EFI System
remaining space Linux filesystem

Encrypt the root with LUKS2
cryptsetup luksFormat /dev/sda2
YES
enter the password
Open
cryptsetup open /dev/sda2 root
This creates /dev/mapper/root.
Create subvolumes Do NOT create a subvolume for snapshots
mkfs.fat -F32 /dev/sda1
mkfs.btrfs /dev/mapper/root
mount /dev/mapper/root /mnt

btrfs su cr /mnt/@
btrfs su cr /mnt/@home
btrfs su cr /mnt/@pkg
btrfs su cr /mnt/@log

umount /mnt
mount -o compress=zstd:1,noatime,subvol=@ /dev/mapper/root /mnt
mount --mkdir -o compress=zstd:1,noatime,subvol=@home /dev/mapper/root /mnt/home
mount --mkdir -o compress=zstd:1,noatime,subvol=@pkg /dev/mapper/root /mnt/var/cache/pacman/pkg
mount --mkdir -o compress=zstd:1,noatime,subvol=@log /dev/mapper/root /mnt/var/log

mount --mkdir /dev/sda1 /mnt/boot

reflector --verbose -c us -a 12 --sort rate --save /etc/pacman.d/mirrorlist

pacstrap -K /mnt base base-devel linux linux-firmware git vim btrfs-progs efibootmgr limine cryptsetup dhcpcd iwd networkmanager reflector bash-completion avahi acpi acpi_call acpid alsa-utils pipewire pipewire-alsa pipewire-pulse pipewire-jack wireplumber sof-firmware util-linux openssh man sudo rsync

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

arch-chroot /mnt

ln -sf /usr/share/zoneinfo/Europe/Sofia /etc/localtime
timedatectl set-ntp true
hwclock --systohc

vim /etc/locale.gen
locale-gen
echo LANG=en_US.UTF-8 > /etc/locale.conf

vim /etc/vconsole.conf
KEYMAP=us

echo arch > /etc/hostname

passwd

useradd -mG wheel john
passwd john

EDITOR=vim visudo

/etc/mkinitcpio.conf

MODULES=(btrfs)
...
HOOKS=(base udev autodetect microcode modconf kms keyboard keymap consolefont block encrypt filesystems fsck)
...

mkinitcpio -P

Setting up Limine bootloader

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

Now we need to create an entry for Limine in the NVRAM:

efibootmgr --create --disk /dev/sda2 --part 1 --label "Arch Linux Limine Bootloader" --loader '\EFI\limine\BOOTX64.EFI' --unicode

efibootmgr -v

N.B. --disk /dev/nvme0n1 --part 1 means /dev/nvme0n1p1

N.B. Do NOT include boot when pointing to Limine Bootloader file.

N.B. In a Limine config, boot():/ represents the partition on which limine.conf is located.

blkid /dev/sda2
cryptsetup luksUUID /dev/sda2

Finally let's make a basic configuration for Limine. Use the command vim /boot/EFI/limine/limine.conf and write inside the following (or at least the first of the two sections):

timeout: 3

/Arch Linux
protocol: linux
path: boot():/vmlinuz-linux
cmdline: quiet cryptdevice=UUID=:root root=/dev/mapper/root rw rootflags=subvol=@ rootfstype=btrfs
module_path: boot():/initramfs-linux.img

/Arch Linux (fallback)
protocol: linux
path: boot():/vmlinuz-linux
cmdline: quiet cryptdevice=UUID=:root root=/dev/mapper/root rw rootflags=subvol=@ rootfstype=btrfs
module_path: boot():/initramfs-linux-fallback.img

cryptsetup luksUUID /dev/sda2

Remember being advised to save an UUID? Now is the time to use it. Replace the above with the UUID of your LUKS container.
Later you will need the UUID of this container, which can be obtained through the command - cryptsetup luksUUID/dev/nvme0n1p2 or the command ls -l --time-style=+ /dev/disk/by-uuid/. Make sure you save this UUID somewhere.

systemctl enable NetworkManager
systemctl enable dhcpcd
systemctl enable iwd
systemctl enable systemd-networkd
systemctl enable systemd-resolved
systemctl enable bluetooth
systemctl enable cups
systemctl enable avahi-daemon
systemctl enable firewalld
systemctl enable acpid
systemctl enable reflector.timer

exit
umount -R /mnt
cryptsetup close root
reboot

Reboot and login as user and run: curl -fsSL https://omarchy.org/install | bash

https://learn.omacom.io/2/the-omarchy-manual/96/manual-installation

good luck!!

[multinomi]

Brilliant solution to resize a standard Omarchy installation post install! This approach is a lot more robust than trying to install Omarchy alongside an existing OS, especially for new users!

however, creating a 2nd EFI partition for Windows is not a normal setup and may cause problems later.

I posted install instructions without using Gparted, since it confused Windows installer. (It could be Intel Mac UEFI specific issue.)

Thank you for the inspiration to find a working solution. ;)

My post: #3349

[TheAhumMaitra]

If you like you can follow my guide : Full guide. Feel free to contribute to this guide if anything is wrong and pardon me for any spelling mistakes!