The Google File System

GFS is a useful first distributed storage paper because the assumptions are explicit: large files, append-heavy workloads, commodity failures, and a master that keeps metadata tractable.

Reading focus: How chunks, chunkservers, and a master split data from metadata. Why workload assumptions can simplify a distributed file system. How leases, replication, and recovery handle common machine failures.

SOSP 2003. Ghemawat et al.. 40 min read, easy difficulty.