Much attention has recently been put on the energy-saving scheme for heterogeneous drive (H-Drive) which combines SSD and HDD. This paper focuses on the energy-efficient file buffering schemes for H-Drive while ensuring disk's lifespan. We propose a frequency-energy based replacement scheme (FEBR for short) by adapting previous replacement algorithm FBR with the help of an energy-cost model. And based on the sliding-window scheme, we also present a self-adaptive disk power management scheme by taking the disk lifespan into account, which adjusts timeout threshold according to the statistical behavior of user accesses. To explore the applicability of the existing replacement schemes ranging from page-based to file-based buffering scheme, we evaluate their effectiveness on energy-efficiency, performance, and HDD lifetime and compare them with our proposed scheme. With extensive experiments on four real-world file usage traces collected in our office, some useful conclusions are drawn: energy-saving in H-Drive is feasible, it can reach as high as 70%~80%; FBR and its variant FEBR, and GDS are the best ones among all those online buffering schemes evaluated while FEBR has some advantages over FBR and GDS; the proposed self-adaptive disk power management scheme can effectively control the disk's lifetime and it is inappropriate to power disk on or off by using those fixed-timeout threshold scheme prevailed previously.%利用组合盘(由固态盘和硬盘构成)进行节能是近年来的一个研究热点.对基于文件粒度的组合盘节能缓存机制开展了研究,利用能量代价模型改编FBR,提出了基于频率和能量的替换算法FEBR；同时,基于滑动窗口机制提出了考虑硬盘寿命的自适应磁盘电源管理机制；为探索现有缓存算法在新硬件结构上的适用性,对过去提出的一系列缓存替换算法在能效、性能、硬盘寿命影响等方面进行了较为全面的比较和评价.通过对收集的4个真实用例数据进行一系列比较实验,得到了如下结论:组合盘节能是可行的,可达70％～80％节能效果；联机替换算法FEBR,FBR以及GDS在所有评价的算法中具有总体最优效果,FEBR略优于FBR和GDS,能耗代价模型可以用于指导算法；所提自适应磁盘管理机制能够较好控制硬盘寿命.
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