Israel Institute of Technology
Modern NAND Flash-based Solid-State Drives (SSD) presents low latency, high throughput, low power consumption and solid-state reliability improvements comparing to traditional magnetic-disk based Hard Disk Drives (HDD). However, due to NAND Flash memory cell characteristics, update-in-place is impossible. Instead, the Flash software layer allocates new storage space whenever data is written, even if it is a slightly modified version of already stored data, e.g., a slightly modified file. Consequently, a logical overwrite entails extensive writing with resulting latency, power and chip endurance costs.