zFS - a scalable distributed file system using object disks

zFS is a research project aimed at building a decentralized file system that distributes all aspects of file and storage management over a set of cooperating machines interconnected by a high-speed network. zFS is designed to be a file system that scales from a few networked computers to several thousand machines and to be built from commodity off-the-shelf components. The two most prominent features of zFS are its cooperative cache and distributed transactions. zFS integrates the memory of all participating machines into one coherent cache. Thus, instead of going to the disk for a block of data already in one of the machine memories, zFS retrieves the data block from the remote machine. zFS also uses distributed transactions and leases, instead of group-communication and clustering software. This article describes the zFS high-level architecture and how its goals are achieved.