{ config, pkgs, threemaModules, ... }: {

  fileSystems."/" = {
    device = "/dev/disk/by-uuid/360a6bc9-fc4e-4803-bd53-69320ac32ac5";
    fsType = "btrfs";
    options = [ "defaults" "subvol=nixos" "noatime" ];
  };

  swapDevices =
    [{ device = "/dev/disk/by-uuid/73f91e99-d856-4504-b6b2-d60f855d6d95"; }];

  # Use the GRUB 2 boot loader.
  boot.loader.grub.enable = true;
  boot.loader.grub.version = 2;
  # boot.loader.grub.efiSupport = true;
  # boot.loader.grub.efiInstallAsRemovable = true;
  # boot.loader.efi.efiSysMountPoint = "/boot/efi";
  # Define on which hard drive you want to install Grub.
  boot.loader.grub.device = "/dev/sda"; # or "nodev" for efi only
}