How to load big datasets like million song dataset into BigData HDFS or Hbase or Hive?
If it's already in the CSV or any format on the linux file system, that PIG can understand, just do a hadoop fs -copyFromLocal  to 
If you want to read/process the raw H5 File format using Python on HDFS, look at hadoop-streaming (map/reduce)
Python can handle 2GB on a decent linux system- not sure if you need hadoop for it.
I have downloaded a subset of million song data set which is about 2GB. However, the data is broken down into folders and sub folders. In the sub-folder they are all in several 'H5 file' format. I understand it can be read using Python. But I do not know how to extract and load then into HDFS so I can run some data analysis in Pig. 
Do I extract them as CSV and load to Hbase or Hive ? It would help if someone can point me to right resource.