Hey Ben,   In a CM-managed cluster, CM will take care of managing and deploying configurations for you (including setting custom options like this). Manually editing the config files is brittle, since CM might push new configs ontop of it.  Anyway, to add custom options, search for "safety valve" in the configuration editor, and you can paste in xml directly.   Note also that these two properties are specific to the client, not the datanode or NN, so you probably want to be dropping this into the " HDFS Client Configuration Safety Valve for hdfs-site.xml" box.   Best, Andrew ... View more

You could try using HttpFS, it acts as a trusted edge node between the cluster and external clients. It's basically a proxy for WebHDFS, so clients can't talk directly to the namenode / datanodes. This is lower performance, but it should be okay for 10-20GB of data.   See: http://archive.cloudera.com/cdh4/cdh/4/hadoop/hadoop-hdfs-httpfs/ ... View more