2. Smoke Test HDFS

See if you can reach the NameNode server with your browser:
```
http://$namenode.full.hostname:50070
```

Try copying a file into HDFS and listing that file:

su $HDFS_USER
/usr/lib/hadoop/sbin/hadoop dfs -copyFromLocal /etc/passwd passwd-test
/usr/lib/hadoop/sbin/hadoop dfs -ls

Test browsing HDFS:

http://$datanode.full.hostname:50075/browseDirectory.jsp?namenodeInfoPort=50070&dir=/&nnaddr=$datanode.full.hostname:8020