A read-disturb management technique for high-density NAND flash memory

Abstract

The read-disturb problem is emerging as one of the main reliability issues for future high-density NAND flash memory. A read-disturb error, which causes data loss, occurs to data in a page when a large number of reads are performed to its neighboring pages in the same block. In this paper, we propose a novel read-disturb management technique which reduces the frequency of expensive data migrations needed for avoiding read-disturb errors. Our technique proactively converts highly skewed read accesses to a small number of blocks into more balanced read accesses to a large number of blocks by intelligently changing data block locations accessed. Our experimental results show that our technique is effective in handling the read-disturb problem, reducing the time overhead of data migrations on average by 50% over an FTL based on the existing read-disturb management technique.