Accessing disk is much slower than accessing memory. As a result, many file syst
ID: 3918193 • Letter: A
Question
Accessing disk is much slower than accessing memory. As a result, many file systems have been designed with various optimizations to improve performance. What is an example of file system performance optimization?
Which of the following statements is incorrect with respect to I/O software layers?
Which of the following statements are true about disks?
A hard disk consists of a stack of aluminum, and alloy, or glass platters, with magnetizable metal oxide. After manufacturing, there is no information whatsoever on the disk. Before the disk can be used, each platter must receive a low-level format done by software. What does this format include?
Clocks (also called timers) are essential to the operation of any multiprogrammed system. They maintain the time of day, and prevent one process from monopolizing the CPU. How are clocks implemented?
Question 11 5 pts Accessing disk is much slower than accessing memory. As a result, many file systems have been designed with various optimizations to improve performance. What is an example of file system performance optimization? caching-i.e. keep in memory a collection of blocks that logically belong on the disk, for performance reasons O block read ahead-i.e. write every modified block to disk as soon as it has been written to the cache O reducing disk arm motion -i.e. try to get blocks into the cache before they are needed O disk defragmentation i.e. putting blocks that are likely to be accessed in a sequence, close to each otherExplanation / Answer
11).caching: - keep in memory a collection of books that logically belong on the disk , for perfomance reasons
The ultimate frequent method employed to decrease the duration of disk elucidated as a collection of books i.e similar kind that is preserved in invisible area .
15). If disks,printers ,keyboards and so on are all interfaced in different phases,every time a new device comes along , the operating system must be modified for the new device-hence a uniform interface is preferable.
The interrupts are periodically employed,and should be unseen apart.linked during the run time.device drivers are specific to OS to issue the particular code for managing it.
16) I think all the given statements are correct.
17).The format consists of a series of concentric tracks, each containing some number of sectors, with short gaps between the sectors.
A sector posses the details employed with drive.
18). for some applications it is esential that data never be lost or corrupted even in the face of disk and cpu errors ;stable storage technology provides a ideal disk, which simply works all the time errors.
Due to this the data corruption might arises which needs to prevent it.the programm unable to run considerable lenght correctly.Generally the seek time is time required for disk controller in detecting a slice of particuler data.Rotational delay is the wait required for a disk to attain the disk sector over read write head.data transfer rate is nothing but how much quick the data can transmit from one to other.
19).the clock is entirely implemented in software including maintaining the time of day, preventing processes from running too long, and accounting for CPU usage.
Mainitaining time of day was not complicated simply it require a counter during every block .A clock is also implemented by offering watchdog timers to the slices of system.