Efficient guaranteed disk request scheduling with fahrrad

Guaranteed I/O performance is needed for a variety of applications ranging from real-time data collection to desktop multimedia to large-scale scientific simulations. Reservations on throughput, the standard measure of disk performance, fail to effectively manage disk performance due to the orders of magnitude difference between best-, average-, and worst-case response times, allowing reservation of less than 0.01% of the achievable bandwidth. We show that by reserving disk resources in terms of utilization it is possible to create a disk scheduler that supports reservation of nearly 100% of the disk resources, provides arbitrarily hard or soft guarantees depending upon application needs, and yields efficiency as good or better than best-effort disk schedulers tuned for performance. We present the architecture of our scheduler, prove the correctness of its algorithms, and provide results demonstrating its effectiveness. Categories and Subject Descriptors D.4.2 [Operating Systems]: Sto...

• Type: Conference
• Year: 2008
• Where: EUROSYS
• Authors: Anna Povzner, Tim Kaldewey, Scott A. Brandt, Richard A. Golding, Theodore M. Wong, Carlos Maltzahn
• Keywords: Disk Performance, Disk Resources, Disk Schedulers, EUROSYS 2008, Software Engineering