An Integrated Memory and SSD Caching I/O Subsystem

Abstract

In a multi-tiered storage system, both page cache and solid-state drives are used as the cache of hard disk drives. However, in the current I/O architecture, page cache and SSD cache are managed independently. Thus, page cache and SSD cache managers make the caching and replacement decisions independently. As a result, system performance is limited due to factors including metadata duplication and improper management of the page cache and SSD cache spaces. To address the limitations of the current I/O architecture, we propose a new I/O architecture to enable the information sharing between the page cache and SSD cache managers. By our proposed architecture, the page cache and SSD cache managers can cooperate with each other so that the overall I/O performance is maximized.