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 flip-flop, What is a flip-flop? Ans. Flip-flop is particu...

What is a flip-flop? Ans. Flip-flop is particular bit memory cell. This stores individual bit information in its true and compliment form. It is the basic block of any sequ

Explain parallel overhead, Parallel Overhead The amount of time needed ...

Parallel Overhead The amount of time needed to organize parallel tasks, as opposed to undertaking useful work. Parallel overhead may comprise factors like:   1) Task start-u

What is the use of digital switch, What is the use of digital switch? ...

What is the use of digital switch? Digital switch: This is a device which handles digital signals generated at or passed via a telephone company’s central office further

What are the mapping techniques, What are the mapping techniques? a)Dir...

What are the mapping techniques? a)Direct mapping b) Associative mapping c)  Set associative mapping

Can we delete a domain, Can you delete a domain, which is being used by dat...

Can you delete a domain, which is being used by data elements? No.

Interrupts - computer architecture, Interrupts Interrupt-request lin...

Interrupts Interrupt-request line o   Interrupt-acknowledge signal o   Interrupt-request signal Interrupt-service routine o   May have no relationship t

Explain executing request using message-passing architecture, Explain the E...

Explain the Executing Requests Using a Message-Passing Architecture Executing requests using a message-passing architecture requires good fundamental client-server programming

Describe the horizontal frequency or cycle, Q. Describe the Horizontal Freq...

Q. Describe the Horizontal Frequency or cycle? Horizontal Frequency: The time to scan one line connecting the right edge to left edge of the screen horizontally is known as t

Self-perception, Mr. X seems to view himself in positive terms (MMPI-2: Ho=...

Mr. X seems to view himself in positive terms (MMPI-2: Ho=38) as a well-functioning person who is capable of dealing with his life and personal challenges (MMPI-2: LSE=41, TRT=39),

What is a metadata, What is a Metadata?  Metadata is information about ...

What is a Metadata?  Metadata is information about a PE. In COM, metadata is communicated by non-standardized type libraries. In .NET, this data is contained in the header port

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