Logical vs. physical disk shadowing

Summary form only given. Bitton and Gray (1988) have defined disk shadowing as a technique for maintaining a set of two or more identical disk images on separate disk drives. Its primary purpose is to enhance reliability and availability of secondary storage by providing multiple paths to redundant data. The current paper demonstrates how disk shadowing can be further improved if not physical page images but logical data sets are mirrored with different clustering strategies on different disks.<
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