A local file system manages files on one machine. A distributed file system (DFS) manages files across many machines while presenting a shared namespace to clients.

When an application reads /data/events/2026-05-24.json, the file may actually be split across dozens of storage nodes. The client sees a path. The distributed file system handles metadata lookup, data placement, replication, recovery, and consistency.

Distributed file systems are common in large analytics clusters, HPC environments, on-premise storage platforms, and systems that need high aggregate throughput over large files. They are not always the right answer in the cloud, where object storage often provides similar durability and scale with far less operational work.

This chapter explains how distributed file systems work, why they are built the way they are, and when to choose one.