A Reliability-Aware Address Mapping Strategy for NAND Flash Memory Storage Systems

Abstract

The increasing density of NAND flash memory leads to a dramatic increase in the bit error rate of flash, which greatly reduces the ability of error correcting codes (ECC) to handle multibit errors. NAND flash memory is normally used to store the file system metadata and page mapping information. Thus, a broken physical page containing metadata may cause an unintended and severe change in functionality of the entire flash. This paper presents Meta-Cure, a novel hardware and file system interface that transparently protects metadata in the presence of multibit faults. Meta-Cure exploits built-in ECC and replication in order to protect pages containing critical data, such as file system metadata. Redundant pairs are formed at run time and distributed to different physical pages to protect against failures. Meta-Cure requires no changes to the file system, on-chip hierarchy, or hardware implementation of flash memory chip. We evaluate Meta-Cure under a real-embedded platform using a variety of I/O traces. The evaluation platform adopts dual ARM Cortex A9 processor cores with 64 Gb NAND flash memory. We have evaluated the effectiveness of Meta-Cure on the new technology file system file system. Experimental results show that the proposed technique can reduce uncorrectable page errors by 70.38% with less than 7.86% time overhead in comparison with conventional error correction techniques.

RT-ROS: A real-time ROS architecture on multi-core processors

“…For example, the angular velocity or electric current based method can be adopted to get a more accurate synchronous motion control. Moreover, many emerging memory and storage techniques have been proposed [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47]. We will study how to utilize them to further optimize the performance of RT-ROS.…”

NVMRA: utilizing NVM to improve the random write operations for NAND-flash-based mobile devices

“…Also, PCM presents much shorter read/write latency compared with NAND flash memory, even though its byte addressability has already made it superior to NAND flash on handling reads/writes of small random data. Flash memory has limited endurance, which can only sustain 10 4 10 5 writes before a failure occurs [30,[39][40][41][42][43][44]. Compared with flash memory, PCM has much better endurance, which is more than 10 6 .…”