{...}: {
  environment.persistence."/srv" = {
    hideMounts = true;
    directories = [
      "/etc/nixos"
      "/var/log"
      "/var/lib/postgresql"
      "/var/lib/acme"
      {
        directory = "/var/lib/nix-sync";
        user = "nix-sync";
        group = "nix-sync";
        mode = "0700";
      }
      {
        directory = "/var/lib/sshd";
        user = "root";
        group = "root";
        mode = "0755";
      }
    ];
    files = [
      "/etc/machine-id"
    ];
  };
}