Data Management Design for Interlaced Magnetic Recording
Data Management Design for Interlaced Magnetic Recording
复制标题
隔行磁记录的数据管理设计
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
D. Du
中科院分区：
文献类型：
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作者：
Fenggang Wu;Baoquan Zhang;Zhichao Cao;Hao Wen;Bingzhe Li;Jim Diehl;Guohua Wang;D. Du
交错磁记录（Interlaced Magnetic Recording，IMR）是一种很有前途的技术，当与热辅助磁记录（Heat-Assisted Magnetic Recording，HAMR）一起使用时，其实现了比叠瓦磁记录（Shingled Magnetic Recording，SMR）更高的数据密度和更低的写入放大。在顶R中，顶部（较窄）轨道和底部（较宽）轨道交错，使得每个底部轨道与两个相邻顶部轨道部分重叠。可以在没有任何写入放大的情况下更新顶部轨道，但是如果两个相邻顶部轨道包含有效数据，则更新底部轨道中的数据块需要阅读和重写两个相邻顶部轨道上的受影响数据。本文研究了IMR的有效数据管理方案。首先，我们设计了一个三阶段数据管理算法，根据磁盘使用情况分三个阶段分配磁盘空间。我们进一步提出了两种技术，顶部缓冲区和块交换，这可以用于IMR，以提高性能的三阶段算法。Top-Buffer利用未分配的顶部磁道空间作为底部磁道更新的缓冲区，而Block-Swap则逐步将底部磁道中的热数据与顶部磁道中的冷数据进行交换。最后，我们提出了我们的数据管理设计IMR，或DMIMR，通过集成顶缓冲区和块交换与三阶段计划。使用Microsoft Research剑桥迹线的评估表明，与三相基线方案相比，DM-IMR可以提高吞吐量并降低所有迹线的写入放大。
Interlaced Magnetic Recording (IMR) is a promising technology which achieves higher data density and lower write amplification than Shingled Magnetic Recording (SMR) when used with Heat-Assisted Magnetic Recording (HAMR). In IMR, top (narrower) tracks and bottom (wider) tracks are interlaced so that each bottom track is partially overlapped with two adjacent top tracks. Top tracks can be updated without any write amplification, but updating a data block in a bottom track requires reading and rewriting of the affected data on the two neighboring top tracks if they contain valid data. We investigate efficient data management schemes for IMR in this paper. First, we design a Three-Phase data management algorithm that allocates disk space in three stages according to disk usage. We further propose two techniques, Top-Buffer and Block-Swap, which can be used in IMR to improve the performance of the Three-Phase algorithm. Top-Buffer opportunistically makes use of unallocated top track space as a buffer for updates to the bottom tracks, while Block-Swap progressively swaps hot data in bottom tracks with cold data in top tracks. Finally, we propose our Data Management design for IMR, or DMIMR, by integrating Top-Buffer and Block-Swap with the Three-Phase scheme. Evaluations with Microsoft Research Cambridge traces show that DM-IMR can increase the throughput and reduce the write amplification for all traces when compared with the Three-Phase baseline scheme.