Advanced commands and distributed data layout to enhance the SSD internal parallelism

Abstract

SSDs have been widely deployed in different areas and become competitive storage devices even for data-intensive applications. They have important performance and endurance requirements and their internal features provide a real potential to fulfil them. The multiple and independent SSD internal components allow parallel access to data at each of the four levels (package-chip-die-plane) but it relies completely on the data layout scheme. We proposed a data layout algorithm based only on the SSD basic operations. It distributes data up to the lowest level to exploit the fine grain internal parallelism and improves the SSD performance. In this paper, we also use advanced commands available on newer SSDs and request scheduling in combination with data layout scheme to provide up to the planes parallelism, taking into account both performance and endurance. The result is a new data layout algorithn to exploit the fine grain SSD internal parallelism. It respects the rules imposed by the wise use of advanced commands and the recommandations of maintaining a wide data distribution. The results show an improvement of performance and a Write Amplification (WA) factor very close to the one using basic operations which indicates a preserved endurance.