Hadoop: best place to set HADOOP_CONF_DIR?

[forrie]

We are rolling out Hadoop nodes. I'd prefer to keep and manage the configuration for each system outside of the HADOOP_HOME location. There is HADOOP_CONF_DIR which can be set - but it's not really clear to me, after reading the scripts and some docs, where the best place to set this is, so that everything that needs to reference HADOOP_CONF_DIR will do so correctly.

For example, there the hadoop-env.sh script, the init.d scripts, etc.

Can someone point me in the right direction. Thanks.
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