Energy-Efficient Cloud Storage using Solid-State Drive Caching

In this paper, we explore ways to save power with Solid-State Drive (SSD) caching. We devise an on-line power monitoring scheme using the Watts Up? Pro power meter to evaluate our implementation. Our frame-work offers high performance by keeping a portion of the working set of processes in a local cache, where data can be accessed faster than when it is stored on the storage server disk. Our results indicate that an SSD cache uses less power in Write Back (WB) mode for both cache hits and cache misses. To improve on the initial power sav-ing, we implement a management policy with Least Re-cently Used (LRU) as the replacement policy for work-loads. We also implement a spin down policy to save power on the storage server when there is low disk activ-ity, such as when the cache is large enough to hold the entire working set of running programs.