Storage-Aware Caching: Revisiting Caching for Heterogeneous Storage Systems

Modern storage environments are composed of a variety of devices with different performance characteristics. In this paper, we explore storage-aware caching algorithms, in which the file buffer replacement algorithm explicitly accounts for differences in performance across devices. We introduce a new family of storage-aware caching algorithms that partition the cache, with one partition per device. The algorithms set the partition sizes dynamically to balance work across the devices. Through simulation, we show that our storage-aware policies perform similarly to LANDLORD, a cost-aware algorithm previously shown to perform well in Web caching environments. We also demonstrate that partitions can be easily incorporated into the Clock replacement algorithm, thus increasing the likelihood of deploying cost-aware algorithms in modern operating systems.