Tiler: An Autonomous Region-Based Scheme with Fast Cleaning for SMR Storage

Shingled Magnetic Recording Disks are emerging as a high-density, non-volatile media which significantly precedes conventional disks in both the storing volume and cost. However, inefficient read-modify-writes (RMWs) greatly challenge the management of SMR disks. This paper for the first time presents a decentralized approach called Tiler to manage the SMR disks by dividing the physical space into small autonomous regions (ARs). Each AR can manage its space allocation, address mapping and cleaning independently. By managing these ARs, Tiler is capable of partitioning a centralized-large-scale cleaning into self-contained-small-scale cleaning. In this design, Tiler not only limits cleaning inside an AR but also eliminates the need of over-provisioned buffer as well as RMWs. Our experimental results show that Tiler can shorten the overall system average response time by up to 47% and improve the space utilization by up to 1.32X.