A general framework for dynamic and automatic I/O scheduling in hard and solid-state drives

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• 作者：Pilar Gonzá ; lez-Fé ; rez^a ; ^{pilar@ditec.um.es" class="auth_mail}Author Vitae ; Juan Piernas^aAuthor Vitae ; Toni Cortes^bAuthor Vitae
• 关键词：I/O scheduler ; DADS ; Simultaneous evaluation ; Virtual disk ; Disk modeling
• 刊名：Journal of Parallel and Distributed Computing
• 出版年：May, 2014
• 年：2014
• 卷：74
• 期：5
• 页码：2380-2391
• 全文大小：2136 K

文摘

The selection of the right I/O scheduler for a given workload can significantly improve the I/O performance. However, this is not an easy task because several factors should be considered, and even the 鈥渂est鈥?scheduler can change over the time, specially if the workload鈥檚 characteristics change too. To address this problem, we present a Dynamic and Automatic Disk Scheduling framework (DADS) that simultaneously compares two different Linux I/O schedulers, and dynamically selects that which achieves the best I/O performance for any workload at any time. The comparison is made by running two instances of a disk simulator inside the Linux kernel. Results show that, by using DADS, the performance achieved is always close to that obtained by the best scheduler. Thus, system administrators are exempted from selecting a suboptimal scheduler which can provide a good performance for some workloads, but may downgrade the system throughput when the workloads change.