Minimizing Write Amplification to Enhance Lifetime of Large-page Flash-Memory Storage Devices

Abstract

Due to the decreasing endurance of flash chips, the lifetime of flash drives has become a critical issue. To resolve this issue, various techniques such as wear-leveling and error correction code have been proposed to reduce the bit error rates of flash storage devices. In contrast to these techniques, we observe that minimizing write amplification is another promising direction to enhance the lifetime of a flash storage device. However, the development trend of large-page flash memory exacerbates the write amplification issue. In this work, we present a compression-based management design to deal with compressed data updates and internal fragmentation in flash pages. Thus, it can minimize write amplification by only updating the modified part of flash pages with the support of data reduction techniques; and the reduced write amplification degree is more significant when the flash page size becomes larger due to the development trend. This design is orthogonal to wear-leveling and error correction techniques and thus can cooperate with them to further enhance the lifetime of a flash device. Based on a series of experiments, the results demonstrate that the proposed design can effectively improve the lifetime of a flash storage device by reducing write amplification.