Mlog: Multi-log Write Buffer upon Ultra-fast SSD RAID
Shucheng Wang, Qiang Cao, Ziyi Lu, Jie Yao · 2022
Parity-based RAID suffering from partial-stripe write-penalty has to introduce write buffer to fast absorb and merge incoming writes, and then flush them to RAID array in batch. However, we experimentally observe that the popular buffering mechanism as Linux RAID journal and partial parity logging (PPL) becomes a bottleneck for ultra-fast SSD-based RAID, and we further uncover that the centralized log-buffer model is the prime cause.