{
  boot.initrd.systemd.enable = true;

  fileSystems."/" = {
    device = "none";
    fsType = "tmpfs";
    options = [
      "defaults"
      "size=4G"
      "mode=755"
    ];
  };

  fileSystems."/persist".neededForBoot = true;

  environment.persistence."/persist" = {
    directories = [
      "/etc/nixos"
      "/etc/secrets"
      "/var/log"
      "/var/lib/nixos"
    ];
    files = [
      "/etc/machine-id"
      "/etc/ssh/ssh_host_rsa_key"
      "/etc/ssh/ssh_host_rsa_key.pub"
      "/etc/ssh/ssh_host_ed25519_key"
      "/etc/ssh/ssh_host_ed25519_key.pub"
    ];
  };

}