Abstract:

NAND Flash based Solid State Drive (SSD) has been utilized in enterprise servers and high performance computing environments due to its various advantages, such as fast access speed, low power consumption, high reliability, etc. Since SSD suffers from poor performance of random writes and limited lifespan, a workload adaptive pagelevel address mapping algorithm, named WAPFTL, is proposed, which can predict the characteristics of incoming requests and dynamically adapt the cache strategy of address mapping information. Experimental results show that WAPFTL can improve the cache hit ratio and reduce the number of expensive extra read/write operations by jointly exploiting the temporal and spatial localities of workloads efficiently. Besides, WAPFTL can also reduce the number of erase operations, thus improving the overall performance of SSD.

Key words: NAND flash;SSD;address mapping;flash translation layer