ReclaiMe Data Recovery Training

RAID Recovery Course - Parity Analysis Test

Parity test for a Promise RAID6 gives:

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

Choose the correct statement

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

Choose the correct statement

A XOR B = B XOR A
A XOR B > B XOR A
A XOR B < B XOR A

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

Full RAID5
RAID 5 with a missing disk
RAID 5 with a blank disk

Which parity function is usually used in a RAID5?

Lempel, Ziv, Welch
Huffman
Reed-Solomon
XOR

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

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

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

A XOR B = B XOR A
A XOR 0 = 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

Check for what parity tests are done

all disk combinations with one disk excluded
each disk separately
full disk set

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

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

Next lesson - Entropy analysis

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