3.3 Storage Devices

Question 1

Define ‘mass storage device’.

Answer 1

Non-volatile storage device that holds the data when the system is powered down (GB or TB)

Question 2

Define ‘internal device’.

Answer 2

Device that is placed inside the computer case or tower

Question 3

Define ‘external device’.

Answer 3

Device that is placed outside the computer case or tower and connected to an external port

Question 4

What is a RAID?

Answer 4

A combination of multiple physical hard disks that is recognised by the operating system

Question 5

Contrast RAID 0 and RAID 1

Answer 5

Raid 0 has good speed and no loss of space on the disks, but provides no data redundancy. RAID 1 provides full redundancy.

Question 6

Describe how RAID 0 works, and the colloquial name.

Answer 6

RAID 0 is called striping, and it works by breaking the file into blocks and spreading the data equally across the 2 (or more) disks. When reading back, it’s a lot faster as it can read from both disks at the same time.

Question 7

Describe how RAID 1 works, and the colloquial name.

Answer 7

RAID 1 is called mirroring, because it writes the exact same block of data to two (and only two) disks at once. This means it is slower on the writing, but still offers a boost when reading as both disks are read at the same time.

Question 8

Describe how RAID 5 works and give its name.

Answer 8

Striping with parity
- 3 or more disks
- There is parity A for blocks A1, A2 and A3, and if there is a drive missing then there can be backwards mathematical calulation to regenerate the information onto a new hard drive
- RAID 5 can only recover from single disk failure

Question 9

Describe how RAID 10 works and give its name.

Answer 9

Stripe of Mirrors
- Striping across Disks 1 and 3, with Disks 2 and 4 mirroring each of those.
- Can survive the loss of two disks

Question 10

Which two RAID configurations are failure resistant?

Answer 10

RAID 1, RAID 5

Question 11

Which RAID configurations are fault tolerant (can function even when a component fails)?

Answer 11

RAID 1, RAID 5, RAID 6

Question 12

What does hot-swappable mean?

Answer 12

A device is able to be removed/replaced without powering off the device, interruption, or losing data (for drives)

Question 13

What is AHCI?

Answer 13

A technical standard developed by Intel that allows hot-swappable capability with SATA devices

Question 14

Why was SATA developed?

Answer 14

As a replacement for PATA as an internal connector

Question 15

List the speeds of Original UHS, UHS 1, 2 and 3

Answer 15

Original: 25MB/s
UHS-1: 108MB/s
UHS-2: 312MB/s
UHS-3: 624MB/s

Question 16

What was the maximum capacity of the original SD cards?

Answer 16

2GB

Question 17

How much data can Standard and LTO Ultrim Tape store, respectively?

Answer 17

140GB data
3TB data

Question 18

What is the oldest form of optical drive, what did it store, and what was its capacitiy?

Answer 18

CD, music, 650-700 MB

Question 19

What is the capacity of a DVD?

Answer 19

4.7GB or 8.4GB in double layer

Question 20

What is the capacity of a Blu-ray Disc?

Answer 20

25GB or 50GB in double layer

Question 21

What does an “R” on the end of a disc abbreviation mean?

Answer 21

Write-once (the writing cannot be erased) e.g. CD-R

Question 22

What does CD-RW mean?

Answer 22

Writing and erasing files is possible.

Question 23

Which CD version is DVD-RW similar to?

Answer 23

CD-RW

Question 24

What two DVD versions are similar but have a different form factor?

Answer 24

DVD-RAM and DVD-RW

Question 25

What CD and DVD versions is BD-RE similar to?

Answer 25

CD-RW and DVD-RW

Question 26

What is the capacity of Blu-ray versions 3 and 4?

Answer 26

100GB and 128 GB

Question 27

What does the 1X speed translate to for CD, DVD and Blu-ray respectively?

Answer 27

CD - 150KB/s
DVD - 1.385 MB/s
Blu-ray - 4.5 MB/s

Question 28

What optical drive speeds on a CD are used for data?

Answer 28

2X, 4X, 16X and 24X