长寿命星载NAND Flash自适应坏块管理策略

针对长期在轨运行设备的存储可靠性问题,提出了一种自适应坏块管理策略。首先对星载NAND Flash存储系统建立马尔可夫可靠性模型,其次根据使用情况预估设备产生的坏块数量,并设置数据存储空间的大小；然后根据设备实际在轨坏块数量动态调整数据存储空间,在确保一定时间内有稳定的存储空间的基础上保持较高的空间利用率；最后对自适应坏块管理策略进行了仿真分析。结果表明,在某一写入速率下,该自适应坏块管理策略的空间利用率不低于85%。

Self-adaptive Management Strategy for Bad Blocks Based on Long Lifetime On-board NAND Flash

Aiming at the storage reliability problem on long-term on-orbit operation equipment,a self-adaptive management strategy for bad blocks was proposed.Firstly,a Markov reliability model is built for the on-board NAND Flash storage system.Secondly,according to the wear condition,the bad block numbers in the device are estimated,and the size of the data storage space is set.Then,based on the actual bad block numbers on orbit,the data storage space is adjusted dynamically,ensuring that a stable storage space is maintained and a higher utilization is achieved within a certain period of time.Finally,the simulation analysis of the self-adaptive management strategy is carried out.The results show that using the strategy at a certain write speed the space utilization rate of the device is not less than 85%.