{
  disk = {
    main = {
      type = "disk";
      device = "/dev/nvme0n1";
      content = {
        type = "gpt";
        partitions = {
          boot = {
            size = "1M";
            type = "EF02"; # for GRUB MBR fallback
          };
          ESP = {
            size = "512M";
            type = "EF00";
            content = {
              type = "filesystem";
              format = "vfat";
              mountpoint = "/boot";
            };
          };
          root = {
            size = "100%";
            content = {
              type = "filesystem";
              format = "ext4";
              mountpoint = "/";
            };
          };
        };
      };
    };
    data1 = {
      type = "disk";
      device = "/dev/sda";
      content = {
        type = "gpt";
        partitions = {
          data = {
            size = "100%";
            content = {
              type = "btrfs";
              extraArgs = [ "-f" ];
              mountOptions = [
                "defaults"
                "nofail"
              ];
              mountpoint = "/data";
            };
          };
        };
      };
    };
    data2 = {
      type = "disk";
      device = "/dev/sdb";
      content = {
        type = "gpt";
        partitions = {
          data = {
            size = "100%";
            content = {
              type = "btrfs";
              extraArgs = [ "-f" ];
              postCreateHook = ''
                btrfs device add -f /dev/disk/by-partlabel/disk-data2-data /mnt/data || true
                btrfs balance start -dconvert=raid1 -mconvert=raid1 /mnt/data || true
              '';
            };
          };
        };
      };
    };
  };
}