ReclaiMe Data Recovery Training

RAID Recovery Course - Parity Analysis Test

Which parity function is usually used in a RAID5?

Reed-Solomon
Huffman
Lempel, Ziv, Welch
XOR

Parity test for a Promise RAID6 gives:

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

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

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

A row of [A,B,P] blocks is even if

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

When to apply parity analysis?

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

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

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

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

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

Parity is a special function calculated over data blocks

true
false

Choose the correct statement

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

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

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

Next lesson - Entropy analysis

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