Optimum Backup Policies with Update Failure at Random Times
Syouji Nakamura, Xufeng Zhao, Cunhua Qian · International Journal of Reliability Quality and Safety Engineering · 2018
In order to ensure the data security, plans of incremental and differential backups are usually set up to save the costs which suffer from full backups. In this paper, we suppose that failures occur at data updating times and backups are implemented only at the end of data updates, and full backups are done at time [Formula: see text], over time [Formula: see text] and update [Formula: see text] to balance the costs of data backup and failure recovery. Using the theory of renewal process, we obtain the expected costs of backup and recovery and the expected cost rates for full backups. Optimum solutions of [Formula: see text] and [Formula: see text] to minimize the expected cost rates are obtained, and their comparisons are discussed from the optimizations of the integrated models in analytical ways.