Abstract: “We present hybridFS file system that provides a hybrid structure, which makes use of performance potentials of NAND flash-based SSD (Solid-State Device). As the technology of flash memory has rapidly improved, SSD is being used in various IT products as a nonvolatile storage media. Applications looking for better I/O performance attempt to achieve desirable bandwidth, by employing SSD to storage subsystems. However, building a large-scale SSD storage subsystem deploys several issues that need to be addressed. Those issues include peculiar physical characteristics related to flash memory and high SSD cost per capacity compared to HDD devices. This paper presents a new form of self-adaptive, hybrid file system, called hybridFS, which properly attempts to address aforementioned issues. The main goal of hybridFS is to combine attractive features of both HDD and SSD devices, to construct a large-scale, virtualized address space in a costeffective way. The performance evaluation shows that h”

Keywords: SSD, transparent file mapping, data section, 2- way extent allocation, data layout