{ config, pkgs, ... }: {
  boot.initrd.luks.devices = {
    "root".device = "/dev/disk/by-uuid/3a0a5071-67ab-4e13-a0b7-d31b86f5e8b1";
    "swap".device = "/dev/disk/by-uuid/6dee6e3c-e2f3-46c5-8751-5fce8c80ed49";
    "backup".device = "/dev/disk/by-uuid/a965933d-516c-46cf-8384-006b1770e46b";
  };

  fileSystems = {
    "/" = {
      device = "/dev/mapper/root";
      fsType = "btrfs";
      options = [ "defaults" "noatime" ];
    };
    "/var/backup/disk" = {
      device = "/dev/mapper/backup";
      fsType = "ext4";
      options = [ "defaults" "noauto" "noatime" ];
    };
    "/boot" = {
      device = "/dev/disk/by-uuid/0065-E4EA";
      fsType = "vfat";
      options = [ "defaults" "noatime" ];
    };
  };

  swapDevices = [{ device = "/dev/mapper/swap"; }];

  # Set Spin-Down times of HDDs
  # To get the disk identifier with `udevadm info -n /dev/sdX | grep ID_SERIAL_SHORT`
  services.udev.extraRules = ''
    ACTION=="add", KERNEL=="sd[a-z]", ENV{ID_SERIAL_SHORT}=="WD-WXH1A89L54LA", RUN+="${pkgs.hdparm}/bin/hdparm -S 60 /dev/%k"
  '';

  # Use the systemd-boot EFI boot loader.
  boot.loader.systemd-boot.enable = true;
  boot.loader.efi.canTouchEfiVariables = true;

}