iSAN : An intelligent storage area network

Abstract

A storage area network (SAN) is a high-speed special-purpose network that interconnects data storage devices and storage-consumers. Present day SANs, based on Fibre Channel or iSCSI, share a common deficiency: Neither of them are aware of the storage-consumer; they merely act as a data transport mechanism. In this thesis one such SAN architecture wherein the SAN is intelligent enough to understand the storage-consumer - to provide the optimal service that better suits the storage-consumer, has been proposed and its benefits are corroborated. The main contributions of this thesis are: (1) how to architect an intelligent SAN that understands the storage-consumers to serve them better; (2) how to realize this abstract architecture using existing technologies; and (3) to demonstrate what benefits one would avail should such an intelligent SAN be available. Our results, draw n from three case studies undertaken, show that iSANs approach yields better benefits as compared to conventional SANs. Also, zSAN approach turned out to be generic enough to capture a wide range of other requirements of SANs. The proposed rSAN architecture is based on group communication systems and protocol composition. The existing technologies that are leveraged in realizing the abstract architecture are Ethernet, LLC and VLAN. Suitability of the proposed architecture is validated by considering three case studies: concurrency control, security and stable storage. Improved solutions are proposed for these dissimilar problems in rSAN context; a wide range of problem applicability and their effective solutions speaks for the generality of iSAN. The proposed solutions are experimentally verified by applying them to storage-consumers like the filesystems.