Utilizing Subpage Programming to Prolong the Lifetime of Embedded NAND Flash-Based Storage
Jung-Hoon Kim, Sang-Hoon Kim, Jin‐Soo Kim · IEEE Transactions on Consumer Electronics · 2018
The flash translation layer (FTL) plays an important role in achieving high performance and reliability for nand flash-based storage devices. To ensure metadata consistency for storage requests, FTL is forced to save its own metadata to nand flash memory. However, a large number of FTL metadata writes can impair the lifetime of nand flash-based storage devices. Even though a small fraction of metadata is updated in the internal memory, FTL should write the whole flash page with the redundant data. In this paper, we utilize the subpage programming (SP) technique to decrease the amount of FTL metadata written to the nand flash memory. We also propose a novel FTL called subpage FTL based on the SP technique to prolong the lifetime of embedded nand flash-based storage. The evaluation results show that SPFTL reduces the written amount of FTL metadata by up to 45.4%, and therefore enhances the lifetime of a storage device by up to 19.3% in real workloads.