❄️ NixOS config

This configuration is based on @SailorSnow's config. He did an amazing job with it - thank you!

This repository contains my personal NixOS configuration, primarily targeting Apple Silicon via Asahi Linux. Home Manager is integrated directly into the NixOS builds.

I am using this configuration as my daily driver on a MacBook Air M1 (8GB RAM / 256GB Storage). It currently includes the experimental Asahi Linux branch with working external display support via USB-C.

This configuration uses ZFS as the root filesystem along with ZRAM. This setup is extremely helpful for devices with limited RAM and storage.

I will guide you through the entire installation process. Please note that these instructions might not be complete, as I wrote them from memory step-by-step and may have overlooked some details. If you encounter any issues, feel free to contact me on Telegram or Matrix: @pengwius:matrix.org. I will be more than happy to help you and update the instructions.

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Installing

0. Shrinking the macOS Partition

If you no longer rely on macOS and want to shrink it as much as possible, use Disk Utility to do so manually. Do not use the Asahi tool for this step, as it reserves too much space for macOS and will not allow you to minimize the partition size fully.

1. Installing NixOS

Follow the steps provided here: https://github.com/nix-community/nixos-apple-silicon/blob/main/docs/uefi-standalone.md.

However, when creating the ext4 partition, only use half of the available free space. Leave the other half unallocated.

You could alternatively use the entire space and shrink the ext4 partition later, but this is unnecessary unless your disk space is so limited that it cannot handle the initial system build (including the kernel). You may want to run nix-collect-garbage -d in the future after the system builds to free up disk space.

2. Installing the Configuration

Clone my configuration into your user home directory:

git clone https://github.com/pengwius/nixos-config 

Replace pengwius with your username in the following files:

• /flake.nix
• /home-manager/home.nix
• /hosts/asahi/configuration.nix
• /hosts/common/users.nix
• /modules/home-manager/gui/firefox.nix

Update fileSystems."/" in /hosts/asahi/hardware-configuration.nix to:

fileSystems."/" = {
  device = "/dev/disk/by-uuid/<ext4 partition uuid>";
  fsType = "ext4";
};

Change the disk UUID in fileSystems."/boot" to match yours, and comment out swapDevices and fileSystems."/home".

You can retrieve your UUID by running lsblk -f or blkid.

Now, rebuild your system by running:

sudo nixos-rebuild switch --flake .#asahi

This will likely take some time, as it needs to compile the entire kernel. Once complete, set a password for your user:

passwd <your username>

Finally, reboot your system.

3. Creating the ZFS Partition

Now, create the ZFS partition in the free space you left in Step 1.

Run the following command:

sudo zpool create \
  -o ashift=12 \
  -O compression=zstd \
  -O atime=off \
  -O xattr=sa \
  -O acltype=posixacl \
  -O encryption=aes-256-gcm \
  -O keyformat=passphrase \
  -O keylocation=prompt \
  zroot /dev/<your free partition (likely nvme0n1p6, but verify this yourself!)>

You will be prompted to enter a password to encrypt the filesystem.

Next, create the ZFS datasets:

sudo zfs create zroot/nixos
sudo zfs create zroot/nixos/home

And set up the mountpoints:

sudo zfs set mountpoint=legacy zroot/nixos
sudo zfs set mountpoint=legacy zroot/nixos/home

4. Migrating the System from ext4 to ZFS

First, mount the ZFS partition:

sudo mount -t zfs zroot/nixos /mnt

Copy the entire system to ZFS:

sudo rsync -aAXHv --numeric-ids \
    --exclude={"/dev/*","/proc/*","/sys/*","/tmp/*","/run/*","/mnt/*","/media/*","/lost+found"} \
    / /mnt

Then copy the home directory:

sudo rsync -aAXHv /home/ /mnt/home

5. Configuring the System on ZFS

Chroot into the system on ZFS:

nixos-enter --root /mnt

Edit /hosts/asahi/hardware-configuration.nix in the config and update fileSystems to:

  fileSystems."/" = {
   device = "zroot/nixos";
   fsType = "zfs";
 };

 fileSystems."/home" = {
   device = "zroot/nixos/home";
   fsType = "zfs";
 };

Mount the EFI partition:

mount /dev/nvme0n1p4 (Check which partition holds YOUR EFI!) /boot

Proceed with the rebuild:

nixos-rebuild boot --flake .#asahi

After this, exit the chroot and reboot the system. It should boot into the ZFS installation.

6. Adding the ext4 Partition to the zpool

Once booted into your fresh ZFS system, you may want to add the remaining ext4 partition to the pool to utilize the full disk space. There is no need to resize partitions; you can simply wipe the ext4 partition and add it to the zpool.

Run:

sudo wipefs -a /dev/nvme0n1p5 (This might differ for you! Check carefully!)

And then:

sudo zpool add zroot /dev/nvme0n1p5

Verify that everything went correctly by running:

zpool list
zfs list

7. Adding Swap

To add swap, uncomment swapDevices in /hosts/asahi/hardware-configuration.nix, and create a ZFS Zvol for swap:

sudo zfs create -V 16G -b $(getconf PAGESIZE) -o compression=off -o logbias=throughput -o sync=always -o primarycache=metadata -o secondarycache=none zroot/swap

Format it as swap:

sudo mkswap /dev/zvol/zroot/swap

Enable it:

sudo swapon /dev/zvol/zroot/swap

Finally, rebuild the system:

sudo nixos-rebuild switch --flake .#asahi

Your NixOS Asahi setup on ZFS should now work perfectly!

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🔧 Build, Test, Update

• Evaluate/check flake:

  nix flake check

• Build system closure (dry):

  nix build .#nixosConfigurations.asahi.config.system.build.toplevel

• Update inputs:

  nix flake update

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🖥️ Host

• asahi: Asahi Linux on Apple Silicon (daily driver)

📦 Repository Structure

• flake.nix/flake.lock: Flake entry and locked inputs
• hosts/
  • asahi/: Host configuration (imports Apple Silicon support)
  • common/: Shared host glue (boot.nix, locale.nix, desktop.nix, users.nix)
• home-manager/: User config and assets; applied via system rebuilds
• modules/
  • modules/nixos/: Reusable NixOS modules (e.g., netdata.nix, minecraft-server-*.nix)
  • modules/home-manager/: Reusable HM modules (e.g., zsh.nix, neovim/, gui/)
• overlays/: Overlays including an unstable package set
• pkgs/: Custom packages (e.g., tentrackule)
• dotfiles/: Misc dotfiles not managed as HM modules

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🧩 Notable Choices

• Wayland compositor: Niri (via services.greetd session)
• Stylix: Used for theming and fonts
• Podman: Enabled (Docker‑compat) with DNS for compose
• Bluetooth: Via BlueZ + Blueman
• Home Manager modules: Zsh, Neovim (nixCats), GUI apps (Firefox, Ghostty, etc.)

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❄️ Notes

This is a personal setup tuned for my hardware and workflow. Feel free to explore and adapt it.