Chapter 13: Mass-Storage Structure (Ch 11 Silberschatz)

Question 1

The bulk of secondary storage for modern computers is provided by

Answer 1

hard disk drives (HDDs) and nonvolatile memory (NVM) devices.

Question 2

Each disk platter has a __________ shape

Answer 2

flat circular shape, like a CD. Common platter diameters range from 1.8 to 3.5 inches. The two surfaces of a platter are covered with a magnetic material.

Question 3

The heads are attached to a __________ that moves all the heads as a unit.

Answer 3

The heads are attached to a disk arm that moves all the heads as a unit.

Question 4

The surface of a platter is logically divided into circular __________, which are subdivided into __________.

Answer 4

The surface of a platter is logically divided into circular tracks, which are subdivided into sectors.

Question 5

The transfer rate is

Answer 5

the rate at which data flow between the drive and the computer.

Question 6

The positioning time, or random-access time, consists of two parts: the time necessary to move the disk arm to the desired cylinder, called the __________, and the time necessary for the desired sector to rotate to the disk head, called the __________.

Answer 6

The positioning time, or random-access time, consists of two parts: the time necessary to move the disk arm to the desired cylinder, called the seek time, and the time necessary for the desired sector to rotate to the disk head, called the rotational latency.

Question 7

Although the disk platters are coated with a thin protective layer, the head will sometimes damage the magnetic surface. This accident is called a

Answer 7

head crash.

Question 8

Because of the write wear, and because there are no moving parts, NAND NVM lifespan is not measured in years but in

Answer 8

Drive Writes Per Day (DWPD)

Question 9

To track which logical blocks contain valid data, the controller maintains a

Answer 9

flash translation layer (FTL). This table maps which physical pages contain currently valid logical blocks. It also tracks physical block state—that is, which blocks contain only invalid pages and therefore can be erased.

Question 10

An NVM (Non-Volatile Memory) device is a type of memory storage that

Answer 10

retains data even when power is removed.