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 other