How does the HDFS architecture provide redundancy?
A.
Storing multiple replicas of data blocks on different DataNodes.
B.
Reliance on RAID at each datanode.
C.
Reliance on SAN devices as a DataNode interface.
D.
DataNodes make copies of their data blocks, and put them on different local disks.
Explanation:
http://bradhedlund.com/2011/09/10/understanding-hadoop-clusters-and-the-network/
(writing files to HDFS)