Real-Time Disk Scheduling for Block-Stripping I 2 0 RAID

T h e emerging of Intell igent I / 0 (120) architecture provides a standard for high-performance I/O subsys-t e m s and introduces intelligence a t t h e hardware level. With a n embedded processor, I 2 0 adaptors can o f l o a d t h e m a j o r 1/0 processing workload f r o m t h e CPU and, a t the s a m e t i m e, increase the 1/0 performance. T h i s paper addresses t h e essential issue in t h e design of disk scheduling for I 2 0 RAID-0 devices. W e explore on-l ine real-time multi-disk scheduling f o r I 2 0 requests and propose highly eff icient algorithms to m i n i m i z e the n u m b e r of deadline violations and, a t the s a m e t i m e, t o improve t h e response t i m e s of requests. T h e proposed methodologies are verified by a series of exper iments u n d e r realistic and randomly generated workloads.