SSD Aware File System Page Cache Algorithms Designs and Implementation to Increase Switch Merge and Reduce Full Merge

摘要

The NAND based SSD is a tremendous challenge for file system page cache management design as it possess inbuilt imbalance in reading and writing speeds. The present disk-based page cache management policies adopt strategies to maximize the page hit ratio and treat the cost of page read and writes are equal rather than fully exploiting the characteristics of the SSD. Therefore there exists slowness in SSD write which eventually affects the SSD endurance. In special cases like in random writes there exists a problem of augmented write amplification resulting in penalty of write performance. Therefore, a new page replacement algorithm is needed for storage systems based on NAND flash memory. The aim of this study is to propose a new page replacement algorithm for operating systems which focuses on reducing the replacement cost and I/O execution time. Trace-driven simulations show that the proposed algorithm performs better than existing algorithms in terms of the replacement cost and I/O execution time.