ReZNS: Energy and Performance-Optimal Mapping Mechanism for ZNS SSD

Today, energy and performance efficiency have become a crucial factor in modern computing environments, such as high-end mobile devices, desktops, and enterprise servers, because data volumes in cloud datacenters increase exponentially. Unfortunately, many researchers and engineers neglect the power consumption and internal performance incurred by storage devices. In this paper, we present a renewable-zoned namespace (ReZNS), an energy and performance-optimal mechanism based on emerging ZNS SSDs. Specifically, ReZNS recycles the remaining capacity of zones that are no longer used by adding a renewable concept into the mapping mechanism. We implemented a prototype of ReZNS based on NVMeVirt and performed comprehensive experiments with diverse workloads from synthetic to real-world workloads to quantitatively confirm power and performance benefits. Our evaluation results present that ReZNS improves overall performance by up to 60% and the total power consumption by up to 3% relative to the baseline on ZNS SSD. We believe ReZNS creates new opportunities to prolong the lifespan of various consumer electronics, such as TV, AV, and mobile devices, because storage devices play a crucial role in their replacement cycle.