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

{
  disko.devices = {
    disk.main = {
      device = "/dev/disk/by-id/ata-Samsung_SSD_860_EVO_500GB_S3Z1NB0K303456L";
      type = "disk";
      content = {
        type = "gpt";
        partitions = {
          boot = {
            size = "1M";
            type = "EF02"; # for grub MBR
            priority = 1; # Needs to be first partition
          };
          ESP = {
            name = "ESP";
            size = "512M";
            type = "EF00";
            content = {
              type = "filesystem";
              format = "vfat";
              mountpoint = "/boot";
            };
          };
          nix = {
            size = "100%";
            content = {
              type = "filesystem";
              format = "ext4";
              mountpoint = "/nix";
            };
          };
        };
      };
    };
    nodev."/" = {
      fsType = "tmpfs";
      mountOptions = [
        "size=2G"
        "defaults"
        "mode=755"
      ];
    };
  };
}