RoLo: A Rotated Logging Storage Architecture for Enterprise Data Centers

We propose RoLo (Rotated Logging), a new logging architecture for RAID10 systems for enhanced energy efficiency, performance and reliability. By spreading destaging I/O activities among short idle time slots and proactively reclaiming the stale logging space, RoLo rotates loggers among a logical logging space pool formed collectively from the free storage space available among mirrored disks. Therefore, without the extra dedicated log disks and the corresponding centralized logging, RoLo eliminates the additional hardware and energy costs, potential single point of failure and performance bottleneck. Furthermore, RoLo prolongs the lifecycle of the disks and improves the system’s energy efficiency by reducing the disk spin up/down frequency. We develop three flavors of RoLo, that is, RoLo-E/R/P, to emphasize energy efficiency, reliability, and performance respectively. Extensive trace-driven evaluations demonstrate the advantages of the three RoLo schemes over both a RAID10 system with centralized logging architecture and a typical RAID10 system.