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

Sort Wars, If quicksort is so quick, why bother with anything else? If bubb...

If quicksort is so quick, why bother with anything else? If bubble sort is so bad, why even mention it? For that matter, why are there so many sorting algorithms?

What do you mean by execution unit, Q. What do you mean by Execution Unit? ...

Q. What do you mean by Execution Unit? Execution unit performs all ALU operations. Execution unit of 8086 is of 16 bits. It also contains the control unit that instructs bus in

Networking, compare 2g , 3g , and 4g also with advantage of 3g and 4g.

compare 2g , 3g , and 4g also with advantage of 3g and 4g.

What is link destruction, What is link destruction? Link destruction is...

What is link destruction? Link destruction is inverse of link creation. When a link is destroyed makes sure the associated objects accessible by other handles or intentionally

Describe the uses of credit cards and smart cards, Credit cards and smart c...

Credit cards and smart cards Credit cards comprise a magnetic stripe on the back made up of iron-based particles in a plastic film. Stripe is split up into 3 tracks which a

What is the meaning of user interaction, a. What is the meaning of user int...

a. What is the meaning of user interaction? What are the dissimilar styles in which forms of interaction can be classified? Give one advantage, disadvantage and an example of every

What is input-output processors, Q. What is Input-output processors? le...

Q. What is Input-output processors? let's briefly summarize the development in area of input/output functions. These can be briefed as below: 1. CPU directly controls a peri

Explain isdn address structure and its working, Draw the ISDN address struc...

Draw the ISDN address structure and explain how the addressing works? Address Structure: The ISDN address structure is demonstrated in figure. ISDN number part has a maximum

Design-centered virtual manufacturing, Design-Centered Virtual Manufacturin...

Design-Centered Virtual Manufacturing This gives manufacturing information to the designer throughout the design phase. In this observing the short term and long time definitio

Rubbers, engineering plastics ,rubbers ,composites

engineering plastics ,rubbers ,composites

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