A processor sends 40 disks I/Os per second, these requests areexponent-distributed, and the average service time of an olderdisk is 20 ms. Answer the following questions:1. On average, how utilized is the disk?2. What is the average time spent in the queue?3. What is the average response time for a disk request,including the queuing time and disk service time?

Answered: A processor sends 40 disks I/Os per…

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

Similar questions

Consider a file system on a disk that has both logical and physical block sizes of 512 bytes. Assume that the information about each file is al ready in memory. For each of the three allocation strategies (contiguous, linked, and indexed), answer these questions: a. How is the logical-to-physical address mapping accomplished in this system? (For the indexed allocation, assume that a file is always less than 512 blocks long.) b. If we are currently at logical block 10 (the last block accessed was block 10) and want to access logical block 4, how many physical blocks must be read from the disk
Consider a disk queue with requests for I/O to blocks on cylinders 98, 183, 37, 122, 14, 124, 65, 67. Suppose SSTF disk scheduling algorithm implemented to meet the requests then the total number of head movements are if the disk head is initially at 53.
Consider a file system on a disk that has both logical and physical block sizes of 512 bytes. Assume that the information about each file is al ready in memory. For each of the three allocation strategies (contiguous, linked, and indexed), answer these questions: a. How is the logical-to-physical address mapping accomplished in this system? (For the indexed allocation, assume that a file is always less than 512 blocks long.) b. If we are currently at logical block 10 (the last block accessed was block 10) and want to access logical block 4, how many physical blocks must be read from the disk
Calculate the number of disk tracks traversed using the SSTF 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.
In Paging, for CPU requests there are two access times, one for accessing page table and one for physical memory accessing. How should we minimize this access time? Explain it with example and also draw the figure which helps to minimize this access time. Also, discuss the importance of minimizing the access time.
QUESTION 3 "For an address book used by a single user, it is suitable to be implemented using traditional file system" True False
8. Consider one disk with 400 cylinders, numbered 0 to 399. Assume the current position of head is at cylinder 130. The request queue is given as follows: 150, 40, 350, 100, 280 For each of the disk-scheduling algorithms given below, show (by plotting in the graphs below) the current position of head based on the disk arm movement to satisfy the above requests, and count the total distance (in cylinders) of the disk arm movement. a. First Come First Served (FCFS) 0 40 100 130 150 Total distance (disk arm movement) = b. Shortest Seek Time First (SSTF) 0 40 100 130 150 Total distance (disk arm movement) = c. LOOK - in the direction of increasing track number 0 40 100 130 150 Total distance (disk arm movement) = 280 280 280 350 350 350 399 399 399 d. Based on questions a-c, specify the best algorithm for the given case above. Also explain TWO (2) reasons why the disk scheduling algorithm important in disk management.
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.
A single-CPU system has four processes, P1, P2, P3 and P4 in the ready queue. The execution times and I/O needs for these processes are given below. All times are in ms. (hint: when a process starts an IO operation, it is removed from the ready queue and put back at the end of the queue only when it completes its IO). Process P1: Arrives at 0ms, needs 23ms of CPU time. Performs I/O for 5ms after 10ms of its execution time, then another 5ms after 20ms of its execution time. Process P2: Arrives at 3ms, needs 12ms of CPU time. Performs I/O for 10ms after 5ms of its execution time. Process P3: Arrives at 1ms, needs 15ms of CPU time. Performs I/O for 1ms after 7ms of its execution time. Process P4: Arrives at 2ms, needs 8ms of CPU time. Performs I/O for 5ms after 4ms of its execution time. We assume that the CPU is idle if no one of these four processes is using it. Using Round Robin scheduling algorithm with a Time Quantum of 4ms and ignoring the context switch time, determine: a) The…
B) For a virtual memory system, the auxiliary memory was of size 8 MByte, and the number of empty entries in the memory page table was 1984. If the page and block sizes were 4 KByte, find: 1- the number of blocks in the main memory. 2- the size of main memory. 3- the number of bits in the physical address,
Consider a disk queue with requests for I/O to blocks on Cylinders: 98 183 37 122 14 124 65 67 Consider SSTF (shortest seek time first) scheduling, the total number of head movements is, if the disk is initially 53. Select one: a.245 b.240 c.236 d.224
Consider a computer system with five memory partitions of 300 KB, 400 KB, 200 KB, 100 KB, and 500 KB (in order), and four processes of 212 KB, 417 KB, 112 KB, and 326 KB (in order). a. How would the "best-fit" algorithm allocate the processes into memory partitions? b. Calculate the total size of internal fragmentation (in KB). Show the steps of your solution.

SEE MORE QUESTIONS

Recommended textbooks for you

Database System Concepts

Computer Science

ISBN:

9780078022159

Author:

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

Publisher:

McGraw-Hill Education

Starting Out with Python (4th Edition)

Computer Science

ISBN:

9780134444321

Author:

Tony Gaddis

Publisher:

PEARSON

Digital Fundamentals (11th Edition)

Computer Science

ISBN:

9780132737968

Author:

Thomas L. Floyd

Publisher:

PEARSON

Database System Concepts

Computer Science

ISBN:

9780078022159

Author:

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

Publisher:

McGraw-Hill Education

Starting Out with Python (4th Edition)

Computer Science

ISBN:

9780134444321

Author:

Tony Gaddis

Publisher:

PEARSON

Digital Fundamentals (11th Edition)

Computer Science

ISBN:

9780132737968

Author:

Thomas L. Floyd

Publisher:

PEARSON

C How to Program (8th Edition)

Computer Science

ISBN:

9780133976892

Author:

Paul J. Deitel, Harvey Deitel

Publisher:

PEARSON

Database Systems: Design, Implementation, & Manag…

Computer Science

ISBN:

9781337627900

Author:

Carlos Coronel, Steven Morris

Publisher:

Cengage Learning

Programmable Logic Controllers

Computer Science

ISBN:

9780073373843

Author:

Frank D. Petruzella

Publisher:

McGraw-Hill Education

SEE MORE TEXTBOOKS