Deck 7: Device Management

Question 1

A seek strategy for an I/O device handler is the predetermined policy that the device handler uses to allocate access to the device among the many processes that may be waiting for it.It determines the order in which the processes get the device; the goal is to keep transfer time to a minimum.

Answer 1

False

Question 2

Blu-ray discs are available in several formats: read-only (BD-ROM),recordable (BD-R),and rewritable (BD-RE).

Answer 2

True

Question 3

Two of the most important measures of optical disc drive performance are sustained data-transfer rate and maximum access time.

Answer 3

False

Question 4

RAID is a set of logical disk drives,viewed as a single physical unit by the operating system.

Question 5

The universal serial bus (USB)controller acts as an interface between the operating system,device drivers,applications,and the devices that are attached via the USB host.

Question 6

RAID begins with the assumption that a small set of large-capacity disk drives is preferable to a larger set of small-capacity disk drives.

Question 7

Device management principles are changing rapidly to accommodate cloud computing.

Question 8

A DVD with a fast data transfer rate will drop fewer frames when playing back a recorded video segment than will a unit with a slower transfer rate.

Question 9

Nested RAID levels,also called hybrid levels,are complex RAID configurations created by combining multiple standard levels.

Question 10

There are many more sectors on an optical disc than on a magnetic disk of the same area.

Question 11

First-come,first-served (FCFS)is the simplest device-scheduling algorithm; it is easy to program and essentially fair to users.

Question 12

An optical disc drive spins at a constant speed-this is called constant linear velocity.

Question 13

In the N-Step SCAN device-scheduling algorithm,any requests that arrive while the arm is in motion are grouped for the arm's next sweep.

Question 14

RAID Level 0 is not considered a true form of RAID because it cannot recover from hardware failure.

Question 15

Seek time is the most important characteristic of a fixed-head disk drive.

Question 16

The job of the I/O control unit is to keep up with the I/O requests from the CPU and pass them down the line to the appropriate control unit.

Question 17

When using DMA,the CPU controls the transfer of data to and from memory over the system bus.

Question 18

The Shortest Seek Time First device-scheduling algorithm moves the arm methodically from the inner to the outer track,servicing every request in its path.

Question 19

Direct access storage devices (DASDs)are devices that can directly read or write to an arbitrary place on a disk.

Question 20

Buffers are used to synchronize the movement of data between the relatively slow I/O devices and the very fast CPU.

Question 21

RAID level ____ requires two different parity calculations.

A) 2
B) 3
C) 5
D) 6

Question 22

The I/O ____ allocates the devices,control units,and channels.

A) scheduler
B) traffic controller
C) device handler
D) director

Question 23

____ peripheral devices are assigned to only one job at a time.

A) Dedicated
B) Shared
C) Virtual
D) Static

Question 24

The USB controller assigns bandwidth to each device depending on its priority.The ____ priority is assigned to real-time exchanges where no interruption in the data flow is allowed,such as video or sound data.

A) highest
B) medium
C) lowest
D) standard

Question 25

The ____ is a hardware flag that must be tested by the CPU to determine when a device has completed an operation.

A) Channel Interrupt Word
B) Channel Status Word
C) Device Status Word
D) Device Polling Word

Question 26

____ uses the same underlying philosophy as shortest job next,where the shortest jobs are processed first and longer jobs are made to wait.

A) LOOK
B) FCFS
C) SSTF
D) SCAN

Question 27

To put data on an optical disc requires a high-intensity laser beam,which burns indentations,called pits,and flat areas,called ____.

A) lands
B) valleys
C) hills
D) lakes

Question 28

____ time is the time required to move the arm of a movable-head magnetic drive into position over the proper track.

A) Search
B) Seek
C) Transfer
D) Access

Question 29

If 2.5 minutes is the maximum access time for a magnetic tape,____ is the average access time.

A) 0.5 minutes
B) 1 minute
C) 1.25 minutes
D) 2 minutes

Question 30

To write data to flash memory,a relatively high voltage is sent through one transistor,called the ____,then through a metal oxide layer and into a second transistor called the control gate,where the charge is stored in a cell until it's erased.

A) parallel port
B) floating gate
C) pit
D) crystalline port

Question 31

A dual-layer,single-sided DVD can hold the equivalent of ____ CDs.

A) 3
B) 8
C) 13
D) 19

Question 32

____ is a way to optimize search times on hard disk drives by ordering the requests once the read/write heads have been positioned.

A) Rotational ordering
B) SSTF
C) C-SCAN
D) LOOK and SCAN

Question 33

A ____,used in RAID Level 2,is a coding scheme that adds extra,redundant bits to the data and is therefore able to correct single-bit errors and detect double-bit errors.

A) Synch code
B) Hamming code
C) Parity code
D) Redundancy code

Question 34

On an optical disc,all sectors are ____.

A) of varying sizes depending upon where you are on the disc
B) larger as you move to the edge
C) smaller as you move to the edge
D) of the same size throughout the disc

Question 35

____ control the transfer of information between the disk drives and the rest of the computer system.

A) System controllers
B) Disk drive controllers
C) System interfaces
D) Disk drive interfaces

Question 36

The number of characters that can be recorded per inch on a magnetic tape is determined by the ____ of the tape.

A) width
B) length
C) density
D) parity

Question 37

The data-transfer rate for an optical disc is measured in ____ per second and refers to the speed at which massive amounts of data can be read from the disc.

A) kilobytes
B) megabytes
C) gigabytes
D) terabytes

Question 38

Transfer rate of a magnetic tape is measured in inches per second (ips)using the following formula: transfer rate = density * ____.

A) block size
B) average access time
C) transport speed
D) sector size

Question 39

The advent of optical discs was made possible by developments in ____ technology.

A) magnetic
B) laser
C) storage
D) silicone

Question 40

Of the three components of access time in a movable-head DASD,____ is the slowest.

A) seek time
B) search time
C) transfer time
D) delay time