anchor.diff:  
   [source,sh]
   ---------------
  -./elasticsearch -Des.path.conf=/opt/elasticsearch/conf/test_node --node.name=test_node 
  +./elasticsearch -Des.path.conf=/opt/elasticsearch/conf/test_node --node.name=test_node
   ---------------
   
   for the flag to take effect.
  
positive.code: ==== Command line flags
  
  Command line flags using single dash notation must be now specified as the first arguments.
  For example if previously using: 
  
  [source,sh]
  ---------------
  
negative.code: Instead, the config file must be named `elasticsearch.yml` and must be located
  in the default `config/` directory, or in the directory specified in the
  `CONF_DIR` environment variable.
  
  ==== `ES_CLASSPATH removed`
  
  The `ES_CLASSPATH` environment variable is no longer used to set the class
  path. External libraries should preferably be loaded using the plugin
  mechanism or, if you really must, be copied to the `lib/` directory.
  