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

Explain cpu based exchange, Explain CPU based exchange. CPU Based Exch...

Explain CPU based exchange. CPU Based Exchange: All the control equipment is replaced with a single processor that must be quite powerful, in centralized control. This should

How much CMOS circuits consume power, CMOS circuits consume power ? An...

CMOS circuits consume power ? Ans. As in CMOS one device is ON and one is Always OFF therefore power consumption is low or can say less than TTL.

Events by which we can program "help texts", What are the events by which w...

What are the events by which we can program "help texts" and display "possible value lists"? -PROCESS ON HELP-REQUEST (POH). -PROCESS ON VALUE-REQUEST (POV).

Addition NO-SIGNS to the Write statement, Suppressing the number signs (+/-...

Suppressing the number signs (+/-) is carried out using the addition NO-SIGNS to the Write statement. Statement is false.

Adding xml files to your page, Step 1: Choose File -> Import XML into Templ...

Step 1: Choose File -> Import XML into Template Step 2: Select the XML file & click Open When an XML file is imported, Dreamweaver merges XML content in Template, which is be

How to copy files from a drive and directory, Q. How to copy files from a d...

Q. How to copy files from a drive and directory? You can copy files from a drive and directory other that the currently selected one. However in that case, you need to speci

How does the xml serializer work, How does the Xml Serializer work?  What A...

How does the Xml Serializer work?  What ACL permissions does a process using it require?   Xml Serializer needs write permission to the system's TEMP directory.

What is a fifo, What is a FIFO? FIFO is otherwise known as 'named pipes...

What is a FIFO? FIFO is otherwise known as 'named pipes'. FIFO (first-in-first-out) is a particular file which is said to be data transient. Once data is read from named pipe,

Explain what are user controls, Briefly explain what user controls are and ...

Briefly explain what user controls are and what server controls are and the differences between the two.   An ASP.NET control (sometimes known as a server control) is a server-

Social media strategy design, For this phase of the project you are require...

For this phase of the project you are required to formulate a social media strategy for a product/service/business/concept/charity...etc. the strategy can include technologies such

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