Biding Energy-Efficient Cloud Storage using Solid-State Drive Caching

In this paper, we explore ways to save power with Device Mapper Cache (DM-Cache). We devise an on- line power monitoring scheme using the Watts Up? Pro power meter to evaluate our implementation. The current version of DM Cache offers high performance by keep- ing 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 preliminary results indicate that DM 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 hybrid cache management policy with Least Recently Used (LRU) as the replacement pol- icy for workloads with temporal locality, and Least Fre- quently Used (LFU) for workloads with no apparent lo- cality. 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.