Suppose that a disk drive has 200 cylinders, numbered 0 to 199. The drive is currently servicing request at cylinder 60 and the previous request was at cylinder 80. The queue has a pending request at cylinder 58, 26, 54, 68, 49, 61, 63, 69 ,24, 14 and 90. Starting from the current head position, what is the total distance (in cylinders) that the disk arm moves to satisfy all the pending requests by using the Shortest Seek Time First algorithm.

Suppose that a disk drive has 200 cylinders, numbered 0 to 199. The drive is currently servicing request at cylinder 60 and the previous request was at cylinder 80. The queue has a pending request at cylinder 58, 26, 54, 68, 49, 61, 63, 69 ,24, 14 and 90. Starting from the current head position, what is the total distance (in cylinders) that the disk arm moves to satisfy all the pending requests by using the Shortest Seek Time First algorithm.

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Related questions

Q: Find the complexity of the greedy algorithm for scheduling the most talks by adding at each step the…

Q: Given a jungle matrix NxM: jungle = [ [1, 0, 0, 0], [1, 1, 0, 1], [0, 1, 0, 0], [1, 1, 1, 1,1 1…

A: 1. Define a function `find_path(jungle)` to find a path through the jungle matrix and create a…

Q: Show that we can solve the telescope scheduling problem in O(n) time even if the list of n…

A: Dear Student, The answer to your question is given below -

Q: Matlab: How do I graph semilogx() multiple times on the same plot? The program reads an uploaded…

A: To graph multiple semilogx plots on the same figure in MATLAB based on the conditions you mentioned,…

Q: A computing system is composed of two servers that are mirrors of each other (for redundancy, so if…

A: Import Libraries:The program starts by importing the NumPy library, which is used for generating…

Q: You have a row of 2n disks of two colors, n dark and n light. They alternate: dark, light, dark,…

A: Answer: I have given answer in the handwritten format.

Q: READ AND SOLVE VERY CAREFULLY WITH PYTHON thanks in advance Given a jungle matrix N*M: jungle = […

A: In the given problem, we are provided with a "jungle" represented as a 2D matrix. The objective is…

Q: You have a large text file containing words. Given any two words, find the shortest distance (in…

A: Query: A query in a file refers to a request for information or data stored in the file. In the…

Q: Given an input parameter n, Alice has an unsorted array A of n n items, and she needs to perform…

A: Given that an input parameter n, Alice has an unsorted array A of n n items, and she needs to…

Q: Many scheduling problems can be solved using greedy algorithms. A classic problem is as follows:…

A: A greedy algorithm is a problem-solving approach that makes locally optimal choices at each step in…

Q: Bulb Switching Problem: We are given n bulbs connected by wires into a single linear sequence. We…

A: A greedy algorithm is an approach to problem-solving where the optimal solution is constructed…

Q: Po.

A: we find the primitive roots of the number 11. The code prints the message "The primitive roots of 11…

Q: There are n stacks of n identical-looking coins. All of the coins in one of these stacks are…

A: ANSWER:-

Q: Identify the k largest of the N items in the priority queue by creating a minimum-oriented priority…

A: Prove for that building a minimum-oriented priority queue of size k then doing N -k replace the…

Q: WhyLie comes up to you and claims that he has invented a super-fast comparison based priority queue.…

A: With one problem, it is always wise to decide how long it will take to do the job. We therefore have…

Q: RC4 has a secret internal state which is a permutation of all the possible values of the vector S…

Q: For the traversal log: {X, Y, Z, W, Y, A, B, C, D, Y, C, D, E, F, D, E, X, Y, A, B, M, N}, a. Find…

A: For the traversal log:{X,Y,Z,W,Y,A,B,C,D,Y,C,D,E,F,D,E,X,Y,A,B,M,N} a. Find maximal forward…

Q: Given a jungle matrix N*M: jungle = [ [1, 0, 0, 0], [1, 1, 0, 1], [0, 1, 0, 0], [1, 1, 1, 1,] ]…

A: Python program with output snapshot and explanation is given below

Q: From a list of participants’ ids, find which id is missing from the list. The participant ids sorted…

A: Pseudocode: Let n be the total numbers in the array The numbers are in the array A[] Input: The…

Concept explainers

Hash Table

A hash table also called a hash map, is a data structure that maps key-value pairs. The hash table can be used in complex systems to provide fast access and compact storage. A hash table is a structure that stores data in an abstract data type kind of associative array. It keeps data in an array format, with a distinct index value for every data value. If the index of the required data is known, then the data can be accessed very easily.

Question

2. Suppose that a disk drive has 200 cylinders, numbered 0 to 199. The drive is currently
servicing request at cylinder 60 and the previous request was at cylinder 80. The queue has
a pending request at cylinder 58, 26, 54, 68, 49, 61, 63, 69 ,24, 14 and 90. Starting from the
current head position, what is the total distance (in cylinders) that the disk arm moves to
satisfy all the pending requests by using the Shortest Seek Time First algorithm.

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

This is a popular solution!

SEE SOLUTION Check out a sample Q&A here

Step 1

VIEW

Step 2

VIEW

Step 3

VIEW

Trending now

This is a popular solution!

Step by step

Solved in 3 steps with 1 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.

Similar questions

PLEASE USE PYTHONGiven a jungle matrix NxM:jungle = [ [1, 0, 0, 0], [1, 1, 0, 1], [0, 1, 0, 0], [1, 1, 1, 1,]]Where 0 means the block is dead end and 1 means the block can be used in the path fromsource to destination.Task:Starting at position (0, 0), the goal is to reach position (N-1, M-1).Your program needs to build and output the solution matrix – a 4x4 matrix with 1’s inpositions used to get from the starting position (0,0) to the ending position (N-1,M-1)with the following constraints:You can only move one space at a timeYou can only in two directions: forward and down.You can only pass thru spaces on the jungle matrix marked ‘1’If you cannot reach the ending position – print a message that you’re trapped in thejungleAlgorithm:If destination is reachedprint the solution matrixElseMark current cell in the solution matrixMove forward horizontally and recursively check if this leads to a solution If there is no solution, move down and recursively check if this leads to a solution If…
For Heap File with a page directory, assume that a page can contain up to 100 directory entries and a page can contain 1000 records, for a file of 1,000,000 records, what is the number of pages to store these records, assuming that on average data pages are filled up 70%? With this data page utilization, what is the number of pages to store the directory, assuming that each directory page is full? Assuming both the directory and the file are stored on disk, what is the I/O cost to insert one record in worst case, and in the average case?
Suppose that a disk drive has 100 cylinders, numbered from 0 to 99. The queue which is maintained is 10, 20, 50, 70, 80 in order. The disk arm is initially at cylinder 40. Starting from the current head position, what is the total distance (head movement) for SSTF algorithms? LOOK
ans in 15 min
A computing system is composed of two servers that are mirrors of each other (forredundancy, so if one fails, it can be restored from the other). Assume that each serverhas an expected MTBF of 500 hours and its continuous uptimes (the average of whichis MTBF) follow an Exponential Distribution. Furthermore, assume that when a serverfails, it takes exactly 10 hours to restore the data from the mirror.(a) Write a program that generates synthetic data showing the failure and restorationtimes for each server over 20 years. You can assume it is always exact 24 hours per dayand exact 365 days per year.
RC4 has a secret internal state which is a permutation of all the possible values of the vector S and the two indices i and j a. Using a straightforward scheme to store the internal state, how many bits are used? b. Suppose we think of it from the point of view of how much information is represented by the state. In that case, we need to determine how may different states there are, then take the log to the base 2 to find out how many bits of information this represents. Using this approach, how many bits would be needed to represent the state?
Given numbers = (66, 74, 83, 87, 89, 40, 32, 77), pivot = 32 What is the low partition after the partitioning algorithm is completed? What is the high partition after the partitioning algorithm is completed?
Calculate the number of disk tracks traversed using the FCFS algorithms for the series of disk track service requests given as 54,36,21,74,46,35,26,67. At the time the first request arrives in the disk request queue, the read/write head is at track 50, moving toward the outer (lower-numbered)tracks. Draw the graph of the movement. Assume that the disk has 100 tracks from 0 to 99.
Subject: Operating Systems
Devise an efficient divide-and-conquer algorithm for the Towers of Hanoi problem when the disks are colored alternately red and blue, and we add the extra rule that no disk may be placed on any other disk of the same color.
READ AND SOLVE VERY CAREFULLY WITH PYTHONthanks in advance Given a jungle matrix N*M:jungle = [[1, 0, 0, 0],[1, 1, 0, 1],[0, 1, 0, 0],[1, 1, 1, 1,]]Where 0 means the block is dead end and 1 means the block can be used in the path from source to destination. Task: (Use Python)Starting at position (0, 0), the goal is to reach position (N-1, M-1).Your program needs to build and output the solution matrix, a 4*4 matrix with 1’s in positions used to get from the starting position (0,0) to the ending position (N-1, M-1) with the following constraints:- You can only move one space at a time.- You can only move in two directions: forward and down.- You can only pass thru spaces on the jungle matrix marked ‘1’If you cannot reach the ending position, print a message that you’re trapped in the jungle Algorithm:If destination is reached print the solution matrixElse Mark current cell in the solution matrix Move forward horizontally and recursively check if this leads to…
For the storing files on tape problem (without frequencies), why does sorting by smallest file size produce the best lookup cost in expectation? Because, for any two files with equal file size, it does not matter what order they are in Because, sorting them is greedy and greedy algorithms usually work Because, for any two files with the larger file preceding the smaller, swapping the files reduces the cost in expectation Because, for any three files that are out-of-order a random permutation of those files reduces the cost in expectation