How to access the disk data, Computer Engineering

Assignment Help:

Q. How to Access the Disk Data?

Disks operate is semi-random mode of operation and generally referenced block wise. The data access time on a disk comprises two major components:

  • Seek time: Time to position head on a particular track. On a fixed head disks it's time taken by electronic circuit to select needed head whereas in movable head disks it's time needed to move head to a specific track.
  • Latency time: This is time needed by a sector to reach below read/write head. On an average it's half of time taken for a rotation by disk.

In addition to seek and latency time the time taken to transfer a (read/write) block of words can be considered however normally it is too small in comparison to seek time and latency and in general disk access time is concerned to be sum of seek time and latency time. Because access time of disks is large so it is advisable to read a sizeable part of data in a single go and so disks are referenced block wise. As a matter of fact you will find that in most of computer system input/output involving disk is given a very high priority. Fundamental reason for such priority is latency time which is needed once the block which is to be read passes below read-write head. It may take time of order of milliseconds to do it again, in turn delaying Input /Output and lowering performance of system.


Related Discussions:- How to access the disk data

What are the values of the slack or surplus variables, Consider the followi...

Consider the following linear programming problem: Minimize:        70M + 40N Subject to:           3M + 7N ≥ 233                             10M + 2N ≥ 254

What are the benefits of using e-commerce, What are the benefits of using e...

What are the benefits of using e-commerce? Basic Benefits of E-Commerce The main benefits are enhancing sales and reducing costs. The other advantages are as follows: 1.

Arrow keys - input commands, When the user is inputting commands into your...

When the user is inputting commands into your shell, it should identify the left, right , up and down arrow keys. To implement this, you will need to use the termios.h library to

Give the syntax of if-else statement, Give the syntax of "if-else" and "sw...

Give the syntax of "if-else" and "switch" statements and explain. if else This is used to decide whether to do something at a special point, or to decide between two courses

Genetic algorithms - artificial intelligence, Genetic Algorithms: In s...

Genetic Algorithms: In such a scenario the evolutionary approach to "Artificial Intelligence" is one of the neatest ideas of all. Whether we have tried to mimic the functionin

Explain time switching, Explain Time Switching. Time Switches: The ...

Explain Time Switching. Time Switches: The principle of a time switch is demonstrated in figure. This connects an incoming n channel PCM highway to an outgoing n channel PC

-bit comparator using combinational logic, Design a 4-bit comparator using ...

Design a 4-bit comparator using combinational logic, and Karnaugh Maps. The inputs of the circuit are two 2-bit numbers. a) Construct the truth table given 2-bits inputs A and B, a

Colour - elements of composition, Colour The use of colour is consider...

Colour The use of colour is considered by many to be one of the most important areas in composition. Colours can be used in isolation or specific combinations to create partic

Process of breadth first search, Process of Breadth first search: It's...

Process of Breadth first search: It's very useful to think of this search as the evolution of the given tree, and how each string of letters of word is found via the search in

Find point-to-point link required in fully connected network, The number of...

The number of point to point links required in a fully connected network for 50 entities is? The number of point to point links needed in a completely connected network for 50

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd