ch9_HDDTech

Question 1

Magnetic disk drive speeds

Answer 1

5400
7200
10 000
15 000

Question 2

How do SSD work

Answer 2

Uses transistors and capacitors to store memory much like RAM sticks

• Multi level cells are less reliable than single level
• SSD rules on how to store data is seperate from the OS
• Cells can be rewritten a infinite number of times
• Trim is the defrag function for SSD

Question 3

What makes a hybrid drive unique

Answer 3

Contains both flash memory and spinning platters. The flash memory is essentially a cache like the cpu

Question 4

What are the different kinds of connectors

Answer 4

SATA 
M.2
mSATA
PCIe
PATA
eSATA

Question 5

What is hot swapping

Answer 5

Connect a HDD without powering down first

Question 6

What does ATA stand for?

Answer 6

Advanced Technology Attachment, refers to any drive with a built in controller

Question 7

Explain PATA

Answer 7

Use of 40 or 80 pin ribbon cable

• 144 Pentabyte Max
• Use Molex power connector
• Anything faster than 66 mbps requires a 80 pin cable
• Drives are set to master, slave…

Question 8

Explain SATA

Answer 8

Serial ATA
15 pins for power
7 pins for data
- Direct connection from device to controller
1.5 Gbps = 150 MBps
3 Gbps = 300 MBps
6 Gbps = 600 MBps

Question 9

Is the advertised speed of a HDD the max speed?

Answer 9

No, it is about 80% of its speed, the remainder is left for overhead

Question 10

What does AHCI stand for?

Answer 10

Advanced Host Controller Interface

Question 11

What is AHCI used for?

Answer 11

Unlocks some of the features for SATA

Needs to be enabled within the BIOS

Question 12

What does NCQ stand for and what is it

Answer 12

Native Command Queuing

Optimizes the disk for an increase in read/write speeds

Question 13

What is NVMe

Answer 13

Non Volatile Memory Express is a translator between the OS and the SSD. It makes the drive appear as a spinning disk drive.

Question 14

What is unique about eSATA

Answer 14

External SATA extends the SATA bus, and is hot swappable. Max length of 2 meters

Question 15

What is RAID 0

Answer 15

Disk Striping - data is spread amongst devices

Question 16

What are the two types of RAID 1

Answer 16

Mirroring
Both disks are written two at the same time, one is primary, the other is the mirror drive.
Duplexing
The disks are written two at the same time, but do not share a RAID controller therefore allowing you to continue to work if one drive fails.

Question 17

What is RAID 5

Answer 17

Disk Striping with Distributed Parity
With a minimum of 3 drives, extra information is strored with data to able it to be rebuilt in the event of failure
Dedicated drive for parity

Question 18

What is RAID 6

Answer 18

Disk Striping with Extra Parity

Similar to RAID 5, but 5 Drives are required and can keep working after two drive have failed.

Question 19

What is RAID 10

Answer 19

1+0 = Nested Striped Mirrors
Requires a minimum of 4 drives
2 pairs are configured as mirrors and striping is done across the two pairs

Question 20

What is RAID 0+1

Answer 20

A mirror of stripes = nested mirrored stripes
Start with 2 RAID 0 arrays
The two RAID 0 pairs then mirror each other
Can survive 2 mechanical failures

Question 21

Outline Hardware RAID

Answer 21

Better than software and can support hot swapping. Configured in the CMOS

Question 22

Outline Software RAID

Answer 22

Requires special software - Windows default does support (Only RAID 0 or 1)
This is taxing on the system