Active log pool for fully associative sector translation

Although NAND-based block devices offer good average performance compared to hard disk drives, their poor worst-case performance can be a serious problem in servers and real-time systems. In order to address it, this study proposes to use an active log pool to isolate the working sectors of each process to different NAND blocks. Doing so reduces the association degree of log blocks, which in turn reduces the worst-case write latency. A trace-driven simulation shows that the worst-case latency is reduced up to 1/9 compared to the original scheme without hurting the average performance severely.