Ceph Explained: The Distributed Storage Backbone Powering Modern Infrastructure

01 — Introduction Note: In 2004, a PhD student at UC Santa Cruz named Sage Weil began writing code at a summer internship at Lawrence Livermore National Laboratory. That code would eventually become Ceph — today one of the most widely deployed open-source distributed storage systems on the planet. Ceph is an open-source, software-defined storage platform designed to deliver object, block, and file storage from a single unified system. Built to be self-healing and self-managing, it targets two challenges that haunt every storage engineer at scale: resilience and growth. It achieves both without proprietary hardware — running entirely on commodity servers connected via standard Ethernet. Its architecture is fundamentally distributed, meaning data is always kept across multiple servers or nodes in a cluster, ensuring high availability, fault tolerance, and horizontal scalability all the way to the exabyte level. At its lowest level, Ceph stores everything as objects and then exposes those