Write off-loading: Practical power management for enterprise storage
Write off-loading: Practical power management for enterprise storage
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DOI：
10.1145/1416944.1416949
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发表时间：
2008-11
期刊：
影响因子：
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通讯作者：
D. Narayanan;Austin Donnelly;A. Rowstron
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文献类型：
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作者：
D. Narayanan;Austin Donnelly;A. Rowstron
在企业数据中心，电力使用是影响服务器密度和总拥有成本的问题。存储使用了很大一部分电力预算，而且目前还没有广泛部署的企业级存储系统节能解决方案。传统观点认为，由于空闲期太短，企业工作负载会使旋转磁盘停机无效。我们对企业数据中心中36个卷的数据块级跟踪进行了为期一周的分析，得出的结论是存在大量空闲时间，并且可以通过使用写卸载修改读/写模式来进一步增加空闲时间。注销允许将降速磁盘上的写入请求临时重定向到数据中心其他位置的永久存储。关键挑战是在不牺牲一致性或故障恢复能力的情况下，在数据块级别透明、高效地执行此操作。我们描述了实现这些目标的注销设计和实现。我们通过在基于机架的试验台上重放我们的轨迹部分来评估它。结果表明，仅在空闲时停止磁盘旋转就可以节省28%-36%的能源，而注销进一步将节省45%-60%的能源。
In enterprise data centers power usage is a problem impacting server density and the total cost of ownership. Storage uses a significant fraction of the power budget and there are no widely deployed power-saving solutions for enterprise storage systems. The traditional view is that enterprise workloads make spinning disks down ineffective because idle periods are too short. We analyzed block-level traces from 36 volumes in an enterprise data center for one week and concluded that significant idle periods exist, and that they can be further increased by modifying the read/write patterns using write off-loading. Write off-loading allows write requests on spun-down disks to be temporarily redirected to persistent storage elsewhere in the data center. The key challenge is doing this transparently and efficiently at the block level, without sacrificing consistency or failure resilience. We describe our write off-loading design and implementation that achieves these goals. We evaluate it by replaying portions of our traces on a rack-based testbed. Results show that just spinning disks down when idle saves 28--36% of energy, and write off-loading further increases the savings to 45--60%.