Asymmetric RAID: Rethinking RAID for SSD Heterogeneity
Ziyang Jiao, Bryan Suk Joon Kim · 2024
Traditional RAID solutions (e.g., Linux MD) balance writes evenly across the array for high I/O parallelism and data reliability. This is built around the assumption that the underlying storage components are homogeneous, both in performance and capacity. However, SSDs, even for the same model, exhibit very different characteristics and degrade over time, leading to severe disk under-utilization.