e-SAFE: An Extensible, Secure and Fault Tolerant Storage System

This paper describes e-SAFE , a scalable utility-driven distributed storage system that offers very high availability at an archival scale and reduces management overhead such as periodic repairs. e-SAFE is designed to provide a storage utility for environments such as large-scale data centers in enterprise networks where the servers experience temporary unavailability (possibly high load, temporary downtimes due to repair or software/hardware upgrades). e-SAFE is based on a simple principle: efficiently sprinkle data all over a distributed storage and robustly reconstruct even when many of them are unavailable. e-SAFE also provides strong guarantee on data-integrity. The use of Fountain codes for replicating file data blocks, an efficient algorithm for fast parallel encoding and decoding over multiple file segments, a utility module for service differentiation and auto-adjustments of design parameters, and a background replication mechanism hiding the cost of replication and dissemination from the user, provide a fast, durable and autonomous storage solution.