What are steps to make a Hadoop cluster Rack aware in hadoop 2.0.3-alpha

[Mohammad Mustaqeem]

Hi,
   Please, give me some link or matter that talks about how to make a
hadoop cluster rack-aware.
I am using Hadoop-2.0.3-alpha.

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*With regards ---*
*Mohammad Mustaqeem*,
M.Tech (CSE)
MNNIT Allahabad