Exploring Hot/Cold Data Separation for Garbage Collection Efficiency Enhancement on OCSSDs

Solid State Drives (SSDs) are widely used in various electronic devices and have gained a significant market share because SSDs do not have mechanical components, have fast access speeds and are less likely to be damaged by external forces. To fulfill the functionalities of conventional storage devices, the limitations of SSDs become prominent and require the Flash Translation Layer (FTL) to manage the NAND flash memory. Nevertheless, the conventional FTL functions without the assistance of the host system, which leads to an information gap and decreased efficiency. Recently, the concept of open-channel SSD (OCSSD) has emerged to allow direct host control over SSD internals. Leveraging the concept of OCSSD, this paper proposes a host-assisted garbage collection enhancement mechanism to facilitate the efficiency of garbage collection through hot/cold data separation, and the proposed mechanism can effectively reduce the number of garbage collections by an average of 60.8%.