JAM: Justifiable Allocation of Memory with Efficient Mounting and Fast Crash Recovery
 for NAND Flash Memory File Systems

Sanam-Shahla Rizvi and Tae-Sun Chung ‎
School of Information and Computer Engineering, Ajou University, Korea   ‎

Abstract: Flash memory is small size, lightweight, shock-resistant, non-volatile, and consumes little power. Flash memory therefore ‎shows promise for use in storage devices for consumer electronics, mobile computers and embedded systems. Even though, ‎flash memory has many attractive features but issues on performance and data integrity are becoming more critical to address ‎by researchers. First, the rapidly increasing capacity of flash memory imposes long mount time delay for normal start-up and ‎in case of crash recovery. Second, large main memory requirement for keeping file system mapping data structure becoming ‎significant issue with growth in size of flash memory. In this paper, we discuss related problems in detail, and propose novel ‎mechanism for high performance and system reliability by effective metadata management, efficient mounting, fast crash ‎recovery, and reduced RAM footprints for log structured NAND flash memory based file systems, called justifiable allocation ‎of memory. The trace driven simulation results show the significantly improved performance for mounting and crash recovery ‎time with reduced main memory space required by our proposed justifiable allocation of memory scheme compared to well-‎known JFFS2 and YAFFS2 flash file systems.  ‎

Keywords: Consumer electronics, embedded systems, memory management, system crash recovery, system reliability, and system ‎performance. ‎