This is the documentation for CDH 4.7.1.
Documentation for other versions is available at Cloudera Documentation.

Installing CDH4 on a Single Linux Node in Pseudo-distributed Mode

You can evaluate CDH4 by quickly installing Apache Hadoop and CDH4 components on a single Linux node in pseudo-distributed mode. In pseudo-distributed mode, Hadoop processing is distributed over all of the cores/processors on a single machine. Hadoop writes all files to the Hadoop Distributed File System (HDFS), and all services and daemons communicate over local TCP sockets for inter-process communication.