ICAP, a new flash wear-leveling algorithm inspired by locality

Abstract

In this paper, we extend a trivial wear-leveling algorithm to reduce the management overhead of leveraging the number of write operations over all data blocks. By exploiting access locality, most parts of a mapping table of a flash translation layer (FTL) keep unchanged since wear leveling is adopted only when a block tends to be unreliable. Because the mapping table is changed rarely, we can reduce the mounting time by record most portion of the mapping table on the flash drive. Furthermore, we can give short codes to the data blocks that erased frequently (because the locality) when recording the erase counts in a log structure. We observe that the algorithm can extend the lifetime of a flash drive and reduce mounting time in most situations.