Flash memory has become the most important storage media in mobile devices, and is beginning to replace hard disks in desktop systems. However, its relatively poor random write performance may cause problems in the desktop environment, which has much more complicated requirements than mobile devices. While a RAM buffer has been quite successful in hard disks to mask the low efficiency of random writes, managing such a buffer to fully exploit the characteristics of flash storage has still not been resolved. In this paper, we propose a new write buffer management scheme called Block Padding Least Recently Used, which significantly improves the random write performance of flash storage. We evaluate the scheme using trace-driven simulations and experiments with a prototype implementation. It shows about 44 % enhanced performance for the workload of MS Office 2003 installation. 1

Peer-to-peer file sharing is popular, but it generates random write traffic to storage due to the nature of swarming. NAND flash memory based Solid-State Drive (SSD) technology is available as an alternative to hard drives for notebook and tablet PCs. As it turns out, random write is extremely detrimental to the lifetime of SSD drives. This paper focuses on the following problem, namely, P2P file downloading when the target of the download is an SSD drive. We make three contributions: first, analysis of write patterns of downloading program to establish the premise of the problem; second, development of a simple yet powerful technique called FlashLite to combat this problem, by automatically converting the random writes to sequential writes; third, showing through performance evaluation using modified eMule file downloading program that FlashLite does change random writes to sequential, and most importantly eliminates about 94 % of erase operations of the original eMule program.