| 摘要 |
A smart flash drive has one or more levels of smart storage switches and a lower level of single-chip flash devices (SCFD's). A SCFD contains flash memory and controllers that perform low-level bad-block mapping and wear-leveling and logical-to-physical block mapping. The SCFD report their capacity, arrangement, and maximum wear-level count (WLC) and bad block number (BBN) to the upstream smart storage switch, which stores this information in a structure register. The smart storage switch selects the SCFD with the maximum BBN as the target and the SCFD with the lowest maximum WLC as the source of a swap for wear leveling when a WLC exceeds a threshold that rises over time. A top-level smart storage switch receives consolidated capacity, arrangement, WLC, and BBN information from lower-level smart storage switch. Data is striped and optionally scrambled by Redundant Array of Individual Disks (RAID) controllers in all levels of smart storage switches. |
