Why is rotational latency not considered in disk scheduling, Operating System

Assignment Help:

Q. Why is rotational latency typically not considered in disk scheduling? How would you alter SSTF, SCAN and C-SCAN to comprise latency optimization?

Answer: Most disks don't export their rotational position information to the host. Even if they did and the time for this information to reach the scheduler would be subject to imprecision and the time consumed by the scheduler is variable therefore the rotational position information would become incorrect. Additional the disk requests are typically given in terms of logical block numbers as well as the mapping between logical blocks and physical locations is very complex.


Related Discussions:- Why is rotational latency not considered in disk scheduling

What is the use of system calls, Q. What is the use of system calls? A...

Q. What is the use of system calls? Answer: System calls permit user-level processes to request services of the operating system.

Why page sizes always powers of 2, Q. Why page sizes always powers of 2? ...

Q. Why page sizes always powers of 2? Answer: Recall that paging is executed by breaking up an address into a page and offset number. It is most competent to break the address

Explain the threadswitchwithdelay function used in netware, Explain the Thr...

Explain the ThreadSwitchWithDelay Function used in Netware ThreadSwitchWithDelay( )   This command is used when threads are waiting for an event or resource but don't want t

Explain the scheduleworktodo function used in netware, Explain the Schedule...

Explain the ScheduleWorkToDo Function used in Netware ScheduleWorkToDo(MyThread Function, arg, workToDo) The ScheduleWorkToDo ( ) function is specific to NetWare 4.0. This c

Explain advantages and inconveniences of ult, ADVANTAGES AND INCONVENIENCES...

ADVANTAGES AND INCONVENIENCES OF ULT Advantages: Thread switching doesn't involve the kernel - no mode switching Scheduling is able to be application specific -

Define secondary memory, Define secondary memory. This memory holds tho...

Define secondary memory. This memory holds those pages that are not there in main memory. The secondary memory is usually a high speed disk. It is called as the swap device, an

Introduction to microprocessors, Let us consider the pining details of the ...

Let us consider the pining details of the 68HC11 as shown below.     Each pin has a defined function, some easy, some complex. A microprocessor designer should understan

Define latency plus seek time, Define Latency plus seek time The total...

Define Latency plus seek time The total time to arrange a disk drive mechanism for a block of data to be read from is its Latency plus seeks time

Prepare gantt charts and determine the average waiting time, Prepare Gantt ...

Prepare Gantt Charts and Determine the Average Waiting Time 1. Classify the interaction among the processes on the basis if degree to which they are aware of each  other's exi

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