DFS

Hadoop's Distributed File System is designed to reliably store very large files across machines in a large cluster. It is inspired by the GoogleFileSystem.

DFS requirements. Summarizes the requirements Hadoop DFS should be targeted for, and outlines further development steps towards achieving this requirements.

Hadoop Upgrade. Describes a step-by-step procedure for manual transition of Hadoop cluster to a newer software version, and outlines enhancements intended to make the upgrade simple and safe.

Here is a brief description of the design and architecture of the Hadoop Distributed File System (HDFS)