ReclaiMe Data Recovery Training

RAID Recovery Course - Parity Analysis Test

Choose the correct statement

A XOR A > 0
A XOR A < 0
A XOR A = 0

Choose the correct statement

A XOR 0 = A
A XOR 0 = 1
A XOR 0 = 0

Choose the property of XOR function due to which "mirrors are always even"

A XOR 0 = A
A XOR A = 0
A XOR B = B XOR A

Choose the property of XOR function due to which "blank disks litter the parity analysis"

A XOR A = 0
A XOR 0 = A
A XOR B = B XOR A

When to apply parity analysis?

after zero and mirror analysis
before zero and mirror analysis
between zero and mirror analysis
after entropy analysis

Parity test for a Promise RAID6 gives:

100% parity in full disk set and 0% parity in all combinations with one disk excluded
0% parity in full disk set and 0% parity in all combinations with one disk excluded
0% parity in full disk set and 100% parity in all combinations with one disk excluded

Look at the picture on the right and guess a RAID level

3-disk RAID 5 with a hotspare
4-disk RAID 5 with one disk missing
full 4-disk Promise RAID6 or full 4-disk RAID5

Given that P is a parity block calculated over A and B data blocks

A XOR B XOR P = 1
A XOR B XOR P = 0

Parity is a special function calculated over data blocks

false
true

Look at the picture on the right and guess the possible RAID level

Full RAID6
RAID 5 with a blank disk
RAID6 with a missing disk
Full RAID 6 with a hotspare

Next lesson - Entropy analysis

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