{
  config,
  lib,
  ...
}: let
  dataDir = "/var/lib/postgresql/16";
in {
  config = lib.mkIf (config.host.postgres.enable && config.host.impermanence.enable) {
    assertions = [
      {
        assertion = config.services.postgresql.dataDir == dataDir;
        message = "postgres data directory does not match persistence";
      }
    ];
    environment.persistence."/persist/system/root" = {
      enable = true;
      hideMounts = true;
      directories = [
        {
          directory = dataDir;
          user = "postgres";
          group = "postgres";
        }
      ];
    };
  };
}