Assignment 8 I/O, File Systems and Security CSCI 5103, Fall 2010 Due December 13, 2010 . Problem 1: Consider a magnetic disk consisting of 20 heads and 400 cylinders. The disk is divided into four 100-cylinder zones, with the cylinders in different zones containing 160, 200, 240, and 280 sectors, respectively. Assume that each sector contains 512 bytes, average seek time between adjacent cylinders in 1 msec, and the disk rotates at 7200 RPM. Calculate (a) disk capacity, (b) optimal track skew, and (c) maximum data transfer rate. Problem 2: Disk requests are made to a disk driver for I/O from cylinders 10, 22, 18, 2, 30, 38, 6, and 40, that order. A seek time takes 6 msec per cylinder moved. How much seek time is needed for servicing these requests for (a) FCFS (b) Shortest Seek Time First (c) Elevator Algorithm (with disk arm moving upward) In all these cases, assume that the arm is initially at cylinder 20. Problem 3:
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This note was uploaded on 03/06/2012 for the course CSCI 5103 taught by Professor Staff during the Fall '08 term at Minnesota.