Secondary Storage

Question 1

What type of data is Secondary Storage?

Answer 1

Non-Volatile, Data is not lost when there is no power

Question 2

What does secondary storage allow for?

Answer 2

Storing a backup copy of data, so that if lost data can be restored

Question 3

What does a Hard disk drive work?

Answer 3

• Consists of metal disks which are coated with a magnetic material
• The disks are divided into tracks which are divided into sectors
• The disks rotate very quickly
• Read/write heads move across the disk surface to access or store data on the disk

Question 4

Why are HDD’s known as a magnetic storage device?

Answer 4

Because the data is stored in magnetic material

Question 5

Advantages of using a Hard Disk Drive?

Answer 5

• They have a high data transfer rate

- Highest storage capacity

Question 6

Disadvantages of using a Hard Disk Drive?

Answer 6

• Not very portable, care has to be taken handling them

- Access times are slower than SSD’s because they have moving parts

Question 7

How do optical storage devices work?

Answer 7

• Has a plastic disk with a mirrored surface
• Data is burned or pressed onto the surface of the disk
• This creates a series of Pits and Lands
• The pits has a value of zero, the lands have a value of one
• Laser beams are used to read the data on the disk since the pits and lands reflect different amounts of light, which are decoded into the original binary data.
• The reader starts reading data on the inside of the disk and works its way to the outside.

Question 8

What are the different types of Optical storage and their storage capacity?

Answer 8

• CD - 650 Mb
• DVD - 4.7 Gb
• Blu-ray - 25 Gb

Question 9

Advantages of using Optical Storage?

Answer 9

• Very portable

- Cheap to produce

Question 10

Disadvantages of using Optical Storage?

Answer 10

• Can be easily damaged
• less storage capacity than a hard disk drive
• Slower access time that Hard Disks and Solid state drives

Question 11

How do Solid State Drives work?

Answer 11

• comprised of NAND flash memory cells arranged in a grid
• has a controller that manages pages/blocks of memory
• data is stored using floating gate transistors
• The transistors can trap and store charge
• data must be read in pages and written/erased in blocks

Question 12

Advantages of using Solid State Drives ?

Answer 12

• They can read, write and access data faster that Hard drives as they have no moving parts
• They are more durable than optical storage/HDD’s

Question 13

Disadvantages of using Solid State Drives ?

Answer 13

• More expensive to buy than Hard Disk Drives

- Tend to be of smaller capacity that Hard Disk Drives

Question 14

Without increasing the overall size how can the capacity of a HDD be increased?

Answer 14

• By adding more platters

- By decreasing the track width