In Hadoop where does the framework save the output of the Map task in a normal Map-Reduce Application?

Question

I am trying to find out where does the output of a Map task is saved to disk before it can be used by a Reduce task.

Note: - version used is Hadoop 0.20

Answer 1

Map reduce framework will store intermediate output into local disk rather than HDFS as this would cause unnecessarily replication of files.