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

Flash memory is small size, lightweight, shock-resistant, non-volatile, and consumes little power. Flash memorytherefore shows promise for use in storage devices for consumer electronics, mobile computers and embedded systems. Eventhough, flash memory has many attractive features but issues on performance and data integrity are becoming more critical toaddress by researchers. First, the rapidly increasing capacity of flash memory imposes long mount time delay for normalstart-up and in case of crash recovery. Second, large main memory requirement for keeping file system mapping datastructure 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, efficientmounting, fast crash recovery, and reduced RAM footprints for log structured NAND flash memory based file systems, calledjustifiable allocation of memory. The trace driven simulation results show the significantly improved performance formounting and crash recovery time with reduced main memory space required by our proposed justifiable allocation ofmemory scheme compared to well-known JFFS2 and YAFFS2 flash file systems