anchor.diff:      DataDir = get_data_dir(),
       do_upgrade_files_from_2_0_to_2_2_0(DataDir),
       do_upgrade_config_from_2_0_to_2_2_0(Config, DefaultConfig, DataDir).
  +
  +upgrade_config_from_2_2_0_to_3_0(Config) ->
  +    ?log_info("Upgrading config from 2.2.0 to 3.0"),
  +    {value, MemcachedConfig} = ns_config:search(Config, {node, node(), memcached}),
  +    MemcachedConfig1 = lists:keystore(log_generations, 1, MemcachedConfig,
  +                                      {log_generations, 20}),
  +    MemcachedConfig2 = lists:keystore(log_cyclesize, 1, MemcachedConfig1,
  +                                      {log_cyclesize, 1024*1024*10}),
  +
  +    [{set, {node, node(), memcached}, MemcachedConfig2}].
   
   search_sub_key(Config, Key, Subkey) ->
       case ns_config:search(Config, Key) of
  
positive.code:                   {set, {node, node(), ns_log}, default_ns_log}
                   ], Result2).
  
  no_upgrade_on_current_version_test() ->
      ?assertEqual([], upgrade_config([[{{node, node(), config_version}, get_current_version()}]])).
  
  
negative.code:              upgrade_config_from_1_8_1_to_2_0(Config)];
          {value, {2,0}} ->
              [{set, {node, node(), config_version}, {2,2,0}} |
               upgrade_config_from_2_0_to_2_2_0(Config)];
          {value, {2,2,0}} ->
              [{set, {node, node(), config_version}, {3,0,0}} |
               upgrade_config_from_2_2_0_to_3_0(Config)]
      end.
  
  upgrade_config_from_1_7_to_1_7_1() ->
  