ReclaiMe Data Recovery Training

RAID Recovery Course - Entropy Analysis Test

Choose that which has the lowest entropy

video
text
parity in a RAID

Check the parameters you should vary in entropy analysis

RAID level
block size
number of disks
disk order

Choose to what you should apply the entropy analysis

each disk separately
full disk set

Check what you can do with entropy analysis

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
detect the first disk in the RAID

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

full 4-disk RAID5, 32 KB block size
4-disk RAID5 with one disk missing, 16 KB block size
full 3-disk RAID5, 16 KB block size, topmost disk doesn't belong to the RAID

What analysis gives you a visual representation of parity blocks?

ratio of zeros analysis
entropy analysis
parity analysis

When to apply entropy analysis?

between zero and mirror analysis
before content analysis
after content analysis

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

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

What has the higher entropy?

parity block in a RAID
data block in a RAID

How to do entropy analysis

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

Next lesson - Parity Analysis

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