LH* Schemes with Scalable Availability

Modern applications increasingly require scalable, highly available 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 insufficient for scalable files, since the probability of more than n failures increases arbitrarily with file size. We propose a new schema termed LH*sa withstanding up to n simultaneous unavailabilities with n scaling with 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.