Virtual Guard: A Track-Based Translation Layer for Shingled Disks.

Virtual Guard (Vguard) is a track-based static mapping translation layer for shingled magnetic recording (SMR) drives. Data is written in-place by caching data from the next track in the shingling direction, allowing direct overwrite of sectors in the target track. This enables Vguard to take advantage of track-level locality, nearly eliminating cleaning for many workloads. We compare performance of Vguard to an available drive-managed SMR drive analyzed and modeled in previous research. Vguard reduces the 99.9% latency by 15× for real-world traces, and maximum latency by 32% for synthetic random write workloads.