SSD 쓰기 감소를 위한 2WPR 캐시 페이지 교체 알고리즘 평가 및 개선

초록

Flash memory-based SSDs have the advantage of faster access speed, lighter weight and smaller physical size than conventional HDDs. On the other hand, it has inherent disadvantages of amplifying writes and limiting the number of erase operation needed before writing. Therefore, researches for effective use of flash memory-based SSDs start with write reduction scheme based on cache policy. As one of such researches, the 2WPR cache page replacement algorithm was published recently. In a FTL environment, this paper analyzes and evaluates the 2WPR algorithm, and suggests improvements. As a result of the test based on large scale field trace data, it shows that the metrics for victim page selection of the improved algorithm reflect about 2% better than those of the original algorithm in terms of write reduction.

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