在一個hybrid-mapped快閃轉譯層裡，它管理快閃記憶體的方式是將整個快閃記憶體分成二個部分：第一部分是data block area，這部分是由快閃記憶體裡大部分的blocks所組成，並以coarse-grained的方式管理；第二部分是log block area，這部分只由快閃記憶體裡少數blocks所組成，並以fine-grained的方式管理。
這篇論文裡，提出一個可支援現代的快閃記憶體且有較好效能的快閃轉譯層。要能夠支援現代的快閃記憶體必須要能夠以log-style的方式對快閃記憶體裡的所有blocks做寫入的動作，並且要有效的使用快閃記憶體裡的spare area。為了達到較好的效能，主要提出三個方法來達成：1. 讓log block可以專屬給特定的data block做寫入的動作，並且讓這樣的方式能夠維持的愈久愈好，因此可以減少需要較高cost回收的情況發生。 2. 提出一個新的回收策略，利用log block的age及reclamation cost這些資訊來選出較好的victim log block做回收。 3. 為了減少高cost的log block回收的機會，因此需要防止entire-block write的寫入會寫到不同的physical blocks。
實驗結果顯示提出的快閃轉譯層能夠減少目前存在的快閃轉譯層最多達到17.8倍的cleaning cost，並且能夠有較穩定的效能表現。此外，在highly-utilized快閃記憶體的情況下，甚至可能能夠勝過page-mapped的快閃轉譯層。

A hybrid-mapped Flash Translation Layer (FTL) partitions the entire flash memory into a large data block area, managed by coarse-grained mapping, and a small log block area, managed by fine-grained mapping. In this paper, an efficient hybrid-mapped FTL supporting modern NAND flash memories is proposed. Modern NAND flash memories support is achieved by enabling log-style writes in all the blocks and the efficient use of spare area. High efficiency is contributed by the three proposed techniques. First, log blocks dedicated to specific data blocks are maintained as long as possible to reduce high-cost block reclamation. Second, a novel cleaning policy with the awareness of both the age and the reclamation cost of the log blocks is used to select victims for reclamation. Third, high-cost shared log block reclamation is reduced by preventing data of an entire-block write from being distributed to multiple physical blocks. The simulation results show the proposed FTL outperforms existing hybrid-mapped FTLs by up to 17.8 times in terms of cleaning cost. Moreover, it has a more stable performance and could outperform page-mapped FTLs in a highly-utilized flash storage.

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