Major Description
Configuration directories can be specified by either setting HADOOP_CONF_DIR or using the --config command line option. However, the hadoop-daemon.sh script will not start the daemons unless the PID directory is separate for each configuration.
The issue is that the code for generating PID filenames is not dependent on the configuration directory. While the PID directory can be changed in hadoop-env.sh, it seems a little unnecessary to have this restriction.