Workload Impact on Shingled Write Disks: All-Writes Can Be Alright

The data density of magnetic disk has been growing at 30% to 50% per year. However, physical limitations will slow this growth unless creative recording techniques can be found. Shingled writing is a promising technique that trades off the inability to update in-place for narrower tracks and thus a much higher data density. In this paper, we look at a variety of potential workloads, drawn from real-world traces, and evaluate their impact on a shingled write disk model. Specifically, we demonstrate the dramatically different effects that different workloads can have upon the opposing approaches of remapping and restoring blocks, and how write-heavy workloads can result in a performance advantage for a shingled-write disk.