Download Data Structures & Object-Oriented Development II - Homework 3: Secondary Storage and more Assignments Data Structures and Algorithms in PDF only on Docsity! CS 2606 Data Structures & OO Devel II Homework 3: Secondary Storage 1 Prepare your answers to the following questions either in a plain text file or in a file that can be opened with Microsoft Word. Submit your file to the Curator system (www.cs.vt.edu/curator) under the heading HW3, by the posted deadline for this assignment. No late submissions will be accepted. 1. [60 pts] Assume a system uses a hard drive with the following physical characteristics: total capacity 128 GB # of platters 8 # of tracks per surface 16384 # of sectors per track 2048 cluster size 4 KB spindle speed 15000 RPM head start time 1 ms track to track seek time 0.01 ms In answering the following questions, express all final time values to the nearest hundredth of a millisecond (8.33 ms). For full credit, you must show and explain all of your calculations. a) What is the average random head seek time for this drive? b) What is the average rotational latency for this drive? c) What is the average total time required to read one randomly-chosen sector from this drive? d) What is the average total time required to read one randomly-chosen cluster from this drive? e) What is the average total time required to read a file of 20 MB from this drive if the clusters are stored as efficiently as possible on the drive? f) What is the average total time required to read a file of 20 MB from this drive if the clusters are randomly scattered on the drive? 2. [20 points] Assume each of the changes described below were made to the design of the drive described in the preceding question, and that no other changes were made. Indicate the effect of the change on the average random head seek time and the average rotational latency time for the drive. The parts are independent. Justify your conclusions if you want credit. a) doubling the rotational speed, and modifying the read/write heads so that they can keep up with the increased transfer rate b) reducing the platter diameter by half, reducing the track spacing by half, reducing the track-to-track seek time by half, and doubling the number of tracks per surface (which would alter the total capacity of the device) 3. [20 points] Download the file FileData.txt from the website. This file contains file sizes and other information about the set of files on a hard disk. The total logical size of the collection of files is actually 20,526,106,311 bytes. Of course, the actual size on disk will be different, due to internal fragmentation. Use the data in the file to calculate the total number of clusters that would be allocated, the total size of the files on disk, and the total number of bytes of disk space that is lost to internal fragmentation, assuming the cluster size is 512 bytes. Repeat for cluster sizes 1024 bytes, 4096 bytes, and 8192 bytes. Report your results in a table like the one given below:
