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 a verification point?, A verification point is a point in a script ...

A verification point is a point in a script that you make to confirm the state of an object across builds of the application-under-test.

Two methods of copying a information document, There are basically two meth...

There are basically two methods of copying: Photocopying This is a modified development of photography. It is quite expensive and slow and is not often used for routine rep

Define dma controller, Define DMA controller. The I/O device interface ...

Define DMA controller. The I/O device interface control circuit that is used for direct memory access is called as DMA controller.

Methods to resolve collision during hashing., What are the two methods to r...

What are the two methods to resolve collision during hashing. The two methods to resolve collision during hashing are: a) Open addressing and b) Chaining.

Conversioin of the decimal number 82.67 into octal number , Conversioin of ...

Conversioin of the decimal number 82.67 into Octal number ? Ans. The binary equivalent is (1010010.10101011) 2 of decimal number 82.67. After that convert each 3-bit binary in

Fundamental change to the cloud to support mobility, Question: The abun...

Question: The abundance of resources and the ease of access to cloud computing can help to bridge the gap the resource gap for mobile computing. Nevertheless some fundamental c

Clarify the operation of iret instruction, Clarify the operation of IRET in...

Clarify the operation of IRET instruction.  What memory locations comprise the vector for an INT 34 instruction? Interrupt return (IRET) instruction is used only with hardware

SERVER, How to configure TSM server

How to configure TSM server

The variables that are declared outside all functions, The variable that ar...

The variable that are declared outside all the functions are called The variables that are declared outside every functions are known as global variable.

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