ReclaiMe Data Recovery Training

RAID Recovery Course - Entropy Analysis Test

Check what you can do with entropy analysis

detect the first disk in the RAID
notice that start offset doesn't equal zero
spot the disks which do not belong to the RAID in question
spot the disks which do not form a parity-based array

Check the criteria of a correct picture in entropy analysis

has several peaks
has one peak per disk
there is one overlap in peaks
peaks do not overlap

What has the higher entropy?

data block in a RAID
parity block in a RAID

How to do entropy analysis

change settings to make pictures match expectations
launch the analysis and wait until ReclaiMe Pro gives you the correct RAID configuration

Look at the picture on the right and choose the most complete configuration description

full 4-disk RAID5, 16 KB block size
full 4-disk RAID5, 32 KB block size
full 4-disk RAID5, 64 KB block size
4-disk RAID5 with one disk missing, 16 KB block size

Choose the correct statement

random data has high entropy
ordered data has high entropy

Check the parameters you should vary in entropy analysis

RAID level
disk order
block size
number of disks

Entropy is a measure of data randomness

true
false

Look at the picture on the right and choose the appropriate description

selected block size is larger than the actual block size
selected number of disks is wrong
selected block size is less than the actual block size

Choose that which has the lowest entropy

video
text
parity in a RAID

Next lesson - Parity Analysis

We have a mailing list in which we talk about interesting cases we encounter and share some tips and tricks.