anchor.diff:      CfgWithoutUUID = [[{some_key, some_value}]],
       CfgWithUUID = [[{Key, <<"uuid">>},
                       {some_key, some_value}]],
  -    Default = [{Key, <<"default uuid">>}],
  -
  -    ?assertEqual([],
  +    Default = [{Key, <<"default uuid">>},
  +               {{node, node(), port_servers}, port_servers_cfg}],
  +
  +    ?assertMatch([{set, {node, _, port_servers}, _}],
                    do_upgrade_config_from_2_3_0_to_3_0(CfgWithUUID, Default)),
   
  -    ?assertEqual([{set, Key, <<"default uuid">>}],
  +    ?assertMatch([{set, {node, _, port_servers}, _}, {set, Key, <<"default uuid">>}],
                    do_upgrade_config_from_2_3_0_to_3_0(CfgWithoutUUID, Default)).
   
   no_upgrade_on_current_version_test() ->
  
positive.code:            [{log_generations, 10},
              {log_cyclesize, 1024*1024*100}]}]],
      UpgradedCfg = upgrade_config_from_2_2_0_to_2_3_0(Cfg),
      ?assertMatch([
                    {set, Key,
                     [{log_generations, 20},
                      {log_cyclesize, 1024*1024*10},
                      {admin_pass, _}]}], UpgradedCfg).
  
negative.code: 
  do_upgrade_config_from_2_3_0_to_3_0(Config, DefaultConfig) ->
      Key = {node, node(), uuid},
      MaybeUUIDUpdate =
          case ns_config:search(Config, Key) of
              false ->
                  {Key, NodeUUID} = lists:keyfind(Key, 1, DefaultConfig),
                  [{set, Key, NodeUUID}];
              _ ->
                  []
          end,
      PortServersKey = {node, node(), port_servers},
      {value, DefaultPortServers} = ns_config:search([DefaultConfig], PortServersKey),
      [{set, PortServersKey, DefaultPortServers} | MaybeUUIDUpdate].
  
  
  search_sub_key(Config, Key, Subkey) ->
      case ns_config:search(Config, Key) of
  