一种面向重尾分布的SSD磁盘调度算法

An I/O scheduling algorithm of SSD based on heavy-tailed distributions

存储设备上的大量文件其长度呈重尾态分布,IO请求的响应延迟和请求大小有着密切关系,并且固态硬盘的IO操作不对称。基于以上几点,在内核NOOP调度算法的基础上提出一种针对重尾数据分布下的IO调度算法。该算法通过减少大量小片请求的等待时间,提高固态硬盘的性能。经实验验证,相比内核的NOOP调度算法,平均响应时间减少17%。

The size of the files stored in the network server has heavy-tailed feature. Access latency is dependent on the size of the accessed files, and the IO operations of Solid State Disk （SSD） are asym- metric. Therefore, based on the kernel NOOP scheduling algorithm, we propose an I/O scheduling al- gorithm of SSD based on the heavy-tailed distributions to improve the performance of SSD access by reducing the waiting time for lots of small files. Experimental results show that the proposed algorithm can reduce response time by 17% on average compared with the kernel NOOP scheduling algorithm.