RAID

Question 1

RAID 0

Answer 1

Disk striping
Min 2 drives
0 functional failures
No redundancy, if one drive fails ALL data is lost

Question 2

RAID 1

Answer 2

Disk mirroring/duplexing
Minimum 2 drives (even number of drives)
1 functional failure
Ultimate safety, but lose storage space
Two 2TB drives only stores 2TB of data

Question 3

RAID 5

Answer 3

Disk striping with distributed parity
Data distributed evenly between all drives
Minimum 3 drives
1 functional failure
If one drive lost, need to replace drive and rebuild the array.
Two failed drives means loss of data
Three 2TB drives will get you 4TB of storage, one drive essentially used for parity

Question 4

RAID 6

Answer 4

Disk striping with extra parity
Minimum 4 drives
Up to 2 functional failure

Question 5

RAID 10 (RAID 1+0)

Answer 5

Nested, striped mirrors
Minimum 4 drives
Sets of mirrored drives striped to each other
Highest speed, reliability, and redundancy
High cost and low efficiency
For every byte of data saved, need two bytes of storage
Up to 2 functional failures

Question 6

RAID 0+1

Answer 6

Nested mirrored drives
Minimum 4 drives
Opposite build of RAID 10
Sets of striped drives mirrored to each other

Question 7

Disk striping

Answer 7

Spreading data between multiple drives (at least 2)

Question 8

Disk striping with parity

Answer 8

Striping with added parity bits that can be used to rebuild data

Question 9

Disk mirroring

Answer 9

Read and write data simultaneously to two drives
One primary drive and one mirror drive
Mirror drive only used if primary fails

Question 10

Disk duplexing

Answer 10

Same as mirrored, but using a different controller for each drive
System continues working even if the primary controller fails
Marginally faster than mirroring