Abstract:Compared with traditional hard disk drives (HDDs), solid-state drives (SSDs) are shock-resistant and quieter, and have lower power consumption, lower access time and latency while HDDs have much higher capacity and are cheaper than SSDs. To have the merits of both sides while avoiding their disadvantages, we propose a hetero-drive to combine SSD and HDD by using SSD as a cache for HDD, which creates more idle time for HDD to shut-down for power-saving. At the same time, we put forth a decay-enforcement replacement algorithm (DE algorithm for short) which takes both recency and pastness effect of accesses into account. The experimental results show that our strategy achieves very competitive performance against those traditional buffer replacement algorithms.