Problem: Hadoop verification script fails: 'Could not reserve enough space for object heap'

This error will occur if the system doesn't have enough available memory to create a Java virtual machine, that is needed to run a mapreduce job using a RxHadoopMR() compute context. This can happen if you have changed the memory settings for mapreduce for the following:

mapred.child.java.opts

mapred.child.java.ulimit

A workaround for the problem is to reset the setting for those options to the default in Cloudera Manager.