Information Sciences, Vol. 179, No. 14. 2009, pp. 2494-2511.
Exploiting the Performance Gains
of Modern Disk Drives by Enhancing Data Locality
Yuhui Deng
Cranfield University Campus, Bedfordshire MK430AL, United Kingdom
Email: deng_derek@emc.com; yuhuid@hotmail.com
Due to the widening performance gap between the RAM and disk drive, a large number of I/O
optimization methods have been proposed and designed to alleviate the impact of the gap. One of the most
effective approaches of improving disk access performance is enhancing the data locality. This is because
the method could increase the hit ratio of disk cache and reduce the seek time and rotational latency. Disk
drives have experienced dramatic development since the first disk drive was announced in 1956. This
paper investigates some important characteristics of modern disk drives. Based on the characteristics and
the observation that data access on disk drives is highly skewed, the frequently accessed data blocks and
the correlated data blocks are clustered into objects and moved to the outer zones of a modern disk drive.
The idea attempts to enhance the spatial locality, improve the efficiency of the aggressive sequential
prefetch, and take advantage of the Zoned Bit Recording (ZBR). An experimental simulation is employed
to investigate the performance gains produced by the enhanced data locality by breaking down the disk
access time into seek time, rotational latency, data transfer time, and hit ratio of the disk cache. The
experimental results provide useful insights into the performance behaviours of a modern disk drive with
enhanced data locality.
Key words: Disk drive; Data Locality; Data access pattern; Block correlation; Data migration;
Performance
1
1 The initial work in this paper was conducted when Yuhui Deng was a research officer in Cranfield
University. This paper was revised and the work was enhanced after Yuhui Deng joined E