A driver-layer caching policy for removable storage devices
Journal
ACM Transactions on Storage
Journal Volume
7
Journal Issue
1
Date Issued
2011
Author(s)
Abstract
The growing popularity of flash memory is expected to draw attention to the limitations of file-system performance over flash memory. This work was motivated by the modular designs of operating system components such as bus and device drivers. A filter-driver-layered caching design is proposed to resolve the performance gap among file systems and to improve their performance with the considerations of flash memory characteristics. An efficient hybrid tree structure is presented to organize and manipulate the intervals of cached writes. Algorithms are proposed in the merging, padding, and removing of the data of writes. The effectiveness of the proposed approach is demonstrated with some analysis study of FATformatted and NTFS-formatted USB flash disks. The proposed cohesive caching policy was implemented as a filter driver in Windows XP/Vista for performance evaluation. In the experiments, a ten-fold or larger performance improvement was usually achieved when the cache size was only 64KB. Other substantial improvements were also observed in the experiments. For example, the proposed design enabled FATformatted and NTFS-formatted flash-memory devices to copy Linux image files 93% and 14% faster than conventional flash drives, respectively. © 2011 ACM.
SDGs
Type
journal article