su - <$hdfs_user>
bash-4.1$ hdfs fsck / | grep 'Under replicated' | awk -F':' '{print $1}' >> /tmp/under_replicated_files
bash-4.1$ for hdfsfile in `cat /tmp/under_replicated_files`; do echo "Fixing $hdfsfile :" ; hadoop fs -setrep 3 $hdfsfile; done