Data Location Optimization for Improvement of Tiered Storage Performance

Abstract

SUMMARY We propose a new method for tiered storage and evaluate its characteristics. In this method, the fast tier is divided into two areas and the data in each area are managed on the basis of two I/O (input/output) measurement periods. When I/Os to these areas increase, the proposed method allocates the frequently accessed areas to a fast tier in advance, thereby improving storage I/O performance. We evaluate the proposed method by simulating storage I/Os and data migration between tiers. When I/O locality is high or frequently accessed areas rarely move, the proposed method is more effective and improves storage I/O performance by up to 44%.