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 python?, Python is an interpreter, interactive, object-oriented pro...

Python is an interpreter, interactive, object-oriented programming language. It is frequently compared to Tcl, P e r l, Scheme or Java. Python combines remarkable power with v

Why does ftp use two standard ports, Why does FTP use two standard ports wh...

Why does FTP use two standard ports whereas other protocols, in general use only one port? Justify. File transfer protocol uses a control connection just to send commands and r

Declare abstract processor arrays, Think about call of two intrinsic functi...

Think about call of two intrinsic functions discussed above for a 32-Processor (4×8) Multicomputer:    The function call NUMBER_OF_PROCESORS () will return 32.

Illustrate why does a tea kettle sing, Q. Illustrate why does a tea kettle ...

Q. Illustrate why does a tea kettle sing? Answer:- There is a little attachment with a hole in it which acts as a whistle. It is inserted into the spout of the kettle as w

Describe the concept of aggregation, Aggregation Aggregation is a spec...

Aggregation Aggregation is a special form of association that models the "part-whole" or "a-part-of" relationship as an aggregate (the whole) and parts. The most important pro

Explain virtual memory, In a memory hierarchy system, data and programs are...

In a memory hierarchy system, data and programs are first stored in secondary or auxiliary memory. Program and its related data are brought in main memory for execution. What if th

Explain about the voice recognition device, Explain about the Voice recogni...

Explain about the Voice recognition device Blind and partially-sighted people can communicate with a computer using microphone and software (keyboard and touch screens can't be

Perform division in binary showing contents of accumulator, Q. Perform divi...

Q. Perform division in binary showing contents of accumulator, B register and Y register during each step. (Accumulator, B, Y are 5-bit registers) 13 / 2

How is a valid user identifier accomplished, How is a valid user identifier...

How is a valid user identifier accomplished? A valid user identifier is accomplished within one or more of given ways: • Provide some password, which only user knows. • P

What is the future in mq if i have 2+exp, It speeds execution of distribute...

It speeds execution of distributed applications. It runs on dissimilar platforms. It time independent. No loss for msg delivery i.e. guarantee delivery.

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