%0 Journal Article
%T Study of Real-time Disk Scheduling for Two-headed Mirrored Disk with Autonomous Heads<br>非固定双头镜像磁盘实时调度算法的研究
%A QIN Xiao
%A PANG Li-ping
%A HAN Zong-fen
%A LI Sheng-li
%A <br>秦啸
%A 庞丽萍
%A 韩宗芬
%A 李胜利
%J 软件学报
%D 1999
%I 
%X A real-time model for two-headed mirrored disks with autonomous heads is proposed in this paper. Two-headed disks (THD) in this system have two independent arms which can seek cylinder autonomously. Three real-time disk-scheduling algorithms are presented for such disk systems. According to simulation experiments, the algorithm which is called ignore missed deadlines (IGM-EDF) has the best performance, because IGM-EDF does not process those real-time requests which have missed deadlines. The comparison between two-headed mirrored disk with fixed heads(FTMD) and the disk system with autonomous heads (ATMD) is also analyzed in this paper. Because two heads in THD can seek cylinder independently, the performance of ATMD is better than that of FTMD.
%K Two-headed mirrored disk with autonomous heads
%K real-time disk scheduling
%K I/O request
%K simulation experiment
%K performance evaluations<br>非固定双头镜像磁盘
%K 实时磁盘调度算法
%K I/O请求
%K 模拟实验
%K 性能评价
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=8240383F08CE46C8B05036380D75B607&jid=7735F413D429542E610B3D6AC0D5EC59&aid=92668649909402D8&yid=B914830F5B1D1078&vid=F3090AE9B60B7ED1&iid=9CF7A0430CBB2DFD&sid=112A5CAF55F27887&eid=15A3E3A739C4EF3F&journal_id=1000-9825&journal_name=软件学报&referenced_num=0&reference_num=21