Let’s try to understand what the exact problems are & why HDFS is not used in cloud. When new instances are launched on the cloud to build a Hadoop cluster they do not have any data associated with them. So one approach is to copy the entire huge dataset on them, which is not feasible due to various reasons including bandwidth, time to copy & associated cost. Secondly after completion of jobs once again you will need to copy the result back before terminating cluster machines otherwise the result will be lost when instances are terminated & you will not get anything. Also due to associated cost running the entire cluster just for data collection is not feasible.