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

Discuss the process of data mining, Discuss the process of data mining? ...

Discuss the process of data mining? The process of data mining having of three stages: (1)The initial exploration (2) Model building or pattern identification with validat

What is the significance of the memory table ''screen'', What is the signif...

What is the significance of the memory table 'SCREEN'? At runtime, attributes for every screen field are stored in the memory table called 'SCREEN'.  We need not declare this

Show the classification of printers, Q. Show the Classification of Printers...

Q. Show the Classification of Printers? Printers can be classified on following bases: a) Impact: Impact printers print by impact of hammers on ribbon (for example Dot-Matri

What is the type of process identifiers, What is the type of Process Identi...

What is the type of Process Identifiers? Identification of the real user Identification of the effective user Identification of the real group Identification

Problem solving in parallel-, Problem Solving In Parallel Introduction ...

Problem Solving In Parallel Introduction to Parallel Computing This section examines how a particular task can be broken into minor subtasks and how subtasks can be answer i

What are local objects, What are local objects? Local objects (Dev clas...

What are local objects? Local objects (Dev class$TMP) are independent of correction & transport system

Define parallel programming, Conventionally software has been written for s...

Conventionally software has been written for serial computation in that programs are written for computers which have a single Central Processing Unit (CPU). Here the problems are

Explain the differences of casex and casez, Explain the differences of case...

Explain the differences of casex and casez over the case statement? casex operator has to be used when both high impedance value (z) and unknown (x) in any bit  has  to  be  t

Projects on cluster computing, Some famous projects on cluster computing ar...

Some famous projects on cluster computing are as follows: High Net Worth Project: (developed by: Bill McMillan, JISC NTI/65 - The HNW Project, University of Glasgow, The prim

What are the characteristics of semiconductor ram memories, What are the ch...

What are the characteristics of semiconductor RAM memories? They are available in a wide range of speeds. Their cycle time range from 100ns to less than 10ns. The

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