Evaluation of Exclusive Data Allocation Between SSD Tier and SSD Cache in Storage Systems
Shinichi Hayashi, Norihisa Komoda · 2014
We proposed and evaluated the storage I/O response time with the exclusive allocation method between SSD for tiered volume and SSD for cache in the storage system utilizing SSD and HDD. In the proposed method, the SSD cache function with exclusive allocation caches only data which is allocated on HDD tier. This enables more data to be allocated on SSD and leads to reduce storage I/O response time. The simulation result shows that the proposed method reduces the storage I/O response time in high I/O locality workload with large SSD capacity. The proposed method reduces the storage I/O response time by up to 23% compared to the combination method of SSD/HDD volume tiering method and SSD cache method without exclusive allocation.