LH* Schemes With Scalable Availability

Modern applications increasingly reqyire scalable, Highly acailable and distributed storage systems. High-availability schemes typically deliver data despite up to n>₌1 simultaneous unavailabilities of the storage nodes (disks, processors with storage, or entire computers), where n is fixed. Such schemes are insuffient for scalable files, since the probability of more than n failures increases arbitrarily with file size. We propose a new schema termed LH*_sa which can withstand up to n simultaneous unavailabilities where n scales with the size of the file. We present LH*_sa file manipulation and recovery algorithms. We discuss the access and storage performance, and variants tuning selected features. We show that LH*_sa files may scale to any number of nodes, keeping the probability of data unavailability arbitrarily small.