Enhanced management method of storage area network (SAN) server with random remote backups

A SAN (storage area network) is a mass storage solution, that is, designed to provide a high-reliability and high-speed network over fiber optic link. This paper is dealing with the stochastic SAN server management method which is focused on reliability. The (remote) backup servers are hooked up by the long-haul network and replace broken main severs immediately. If the SAN servers are represented as "machines", this system can be solved by using the stochastic maintenance model with main unreliable and random auxiliary spare (remote backup) machines, subject to random breakdowns, repairs, and two replacement policies: one for busy and another for idle or vacation periods. When the repair facility is not available because of the given conditions, auxiliary machines are being used for backups. Unlike existing models, the availability of auxiliary machines is changed for each activation of the system. Analytically tractable results are obtained by using a duality principle (which enables us to treat a more rudimentary system), semiregenerative analysis, and multivariate marked renewal processes. The results are demonstrated in the framework of optimized SAN server allocation problems with unreliable backup servers.