1. we propose two approaches, namely, concentrated mapping and postponed reclamation, to effective reduce the valid page copies.
2.In order to reduce valid page copies,concentrated mappingis utilized to store the written data and its updated data in the same physical block, and postponed reclamationis adopted to postpone the time consuming garbage collection.
3.Specifically, in our approach, concentrated mapping uses the page-level mapping, so the write constraints of MLC NAND flash can be satisfied. The corresponding mapping table is stored in the spare area of the newly allocated pages while the page mapping table indices are recorded in the RAM.
(page level mapping reduce space way)
4.section 3, last paragraph:Our observation is that: page-level mapping approach is necessary in design of MLC flash translation layer.
5.将page mapping table 存到了page spare area,从图可以看出来