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 is orbix?, Orbix is a CORBA ORB (Object Resource Broker) - a commercia...

Orbix is a CORBA ORB (Object Resource Broker) - a commercial software product which helps programmers builds distributed applications. Orbix is an execution of the OMG's (Object Ma

Show the decimal representation in computers, Binary number system is most ...

Binary number system is most common for computer due to two stable states of its components. However unfortunately this isn't a very natural system for us as we deal with decimal n

Paging, Hardware Support for paging

Hardware Support for paging

display the contents of the file grade, a) Input names of students from th...

a) Input names of students from the user, terminated by "ZZZ", 0, 0, 0 and create a data file grades with records of the following form: Student (string), test1 (integer), test2 (i

Illustrate about the single inheritance, Illustrate about the single inheri...

Illustrate about the single inheritance During inheritance, superclass feature may by override by a subclass defining that feature with the same name. The overriding features (

Explain characteristics in java for e-commerce applications, Explain the ch...

Explain the characteristics and utilities available into java that makes it appropriate for developing e-commerce applications. Following are the characteristics and utilities

Difference between the specparam and parameter constructs, What is the diff...

What is the difference between the specparam and parameter constructs? Specparam is a special kind of parameter which is intended to specify only timing and the delay values. K

Illustrate about system memory-management mode, Memory - management mode ...

Memory - management mode System memory-management mode (SMM) is on the same level as protected mode, real mode and virtual mode though it is provided to function as a manager

Write a program to find 2''s complement of a binary number, Q. Write a pro...

Q. Write a program to find 1's and 2's complement of a Binary number. Perform necessary checking that if entered number is not a valid number, ask user to enter valid Binary n

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