Question - What is a block in HDFS and what is its default size in Hadoop 1 and Hadoop 2? Can we change the block size?
Answer -
Blocks are smallest continuous data storage in a hard drive. For HDFS, blocks are stored across Hadoop cluster.
- The default block size in Hadoop 1 is: 64 MB
- The default block size in Hadoop 2 is: 128 MB