disko/example/hybrid-tmpfs-on-root.nix

{ disks ? [ "/dev/sda" ], ... }:
{
  disk.main = {
    device = builtins.elemAt disks 0;
    type = "disk";
    content = {
      type = "table";
      format = "gpt";
      partitions = [
        {
          name = "boot";
          type = "partition";
          start = "0";
          end = "1M";
          flags = [ "bios_grub" ];
        }
        {
          type = "partition";
          name = "ESP";
          start = "1M";
          end = "512M";
          bootable = true;
          content = {
            type = "filesystem";
            format = "vfat";
            mountpoint = "/boot";
          };
        }
        {
          name = "nix";
          type = "partition";
          start = "512M";
          end = "100%";
          part-type = "primary";
          content = {
            type = "filesystem";
            format = "ext4";
            mountpoint = "/nix";
          };
        }
      ];
    };
  };
  nodev."/" = {
    fsType = "tmpfs";
    mountOptions = [
      "size=2G"
      "defaults"
      "mode=755"
    ];
  };
}