An Informal Publication from a University Research Community Devoted to Advancing the State of the Art in Storage Systems and to Efficiently Integrating

Freeblock scheduling is a new approach to utilizing more of disks’ potential media bandwidths. By filling rotational latency periods with useful media transfers, 20-50% of a never-idle disk’s bandwidth can often be provided to background applications with almost no effect on foreground response times. This paper describes freeblock scheduling and demonstrates its value with simulation studies of two concrete applications: free segment cleaning and free data mining. Free segment cleaning often allows an LFS file system to maintain its ideal write performance when cleaning overheads would otherwise cause up to factor of three performance decreases. Free data mining can achieve 4570 full disk scans per day on an active transaction processing system, with no effect on its disk performance. Secure Continuous Biometric-Enhanced Authentication