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

Name the processes of oom, Name the processes of OOM In OOM the modelli...

Name the processes of OOM In OOM the modelling passes through the given processes: System Analysis System Design Object Design, and Final Implementation.

Find out data changing from special code to temporal code, Data can be chan...

Data can be changed from special code to temporal code by using ? Ans. By using Shift Registers data can be changed from special code to temporal code. A Register wherein data ge

Interfacing of keyboards, Q. Interfacing of keyboards? The keyboard emp...

Q. Interfacing of keyboards? The keyboard employs a special Input/output port which is similar to a serial port however doesn't explicitly follow the RS-232 serial port standar

What is computer motherboard, If you open your computers case, the motherbo...

If you open your computers case, the motherboard is the flat, rectangular piece of circuit board to which the whole thing seems to connect to for one reason or one another. It'

What do you mean by loader, Q. What do you mean by Loader? Loader is a ...

Q. What do you mean by Loader? Loader is a program that assigns absolute addresses to program. These addresses are produced by adding the address from where program is loaded i

What are the advantages of ccs over in-channel signalling, What are the adv...

What are the advantages of CCS over in-channel signalling? The advantages of CCS over in-channel signalling are given below: a. Information can be exchange among the process

Give regular expression for real number, Develop a regular expression for R...

Develop a regular expression for Real number and Real number with optional fraction (i) A regular expression for real number is [+ | -] (d)+. (d)+ (ii) A regular expression

Microprocessor, overlapping segmentation process in 8086

overlapping segmentation process in 8086

C, Write a ‘C’ functions to arrange the elements of an integer array in suc...

Write a ‘C’ functions to arrange the elements of an integer array in such a way that all the negative elements are before the positive elements. The array is passed to it as an arg

Explain the term - strong typing and weak typing, Explain the term - Strong...

Explain the term - Strong Typing and  Weak Typing Strong Typing : When any operation upon an object can be checked during compile time, when type is confirmed forcefully.

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