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RAID Recovery Course - Entropy Analysis Test
Check what you can do with entropy analysis
spot the disks which do not form a parity-based array
notice that start offset doesn't equal zero
spot the disks which do not belong to the RAID in question
detect the first disk in the RAID
Check RAID types to which entropy analysis is applied
RAID6
RAID0
RAID10
JBOD
RAID1
RAID5
Look at the picture on the right and choose the most complete configuration description
full 3-disk RAID5, 16 KB block size, topmost disk doesn't belong to the RAID
full 4-disk RAID5, 32 KB block size
4-disk RAID5 with one disk missing, 16 KB block size
Choose to what you should apply the entropy analysis
each disk separately
full disk set
Look at the picture on the right and choose the most complete configuration
full 4-disk RAID6, 256 KB block size
full 4-disk RAID5, 256 KB block size
full 4-disk RAID6, 128 KB block size
full 4-disk RAID5, 128 KB block size
What has the higher entropy?
parity block in a RAID
data block in a RAID
Check the parameters you should vary in entropy analysis
RAID level
number of disks
disk order
block size
Check what you can get with entropy analysis
disk order ideas
original number of disks
block size
spot asynchronous RAIDs
spot synchronous RAIDs
Entropy is a measure of data randomness
false
true
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
Next lesson - Parity Analysis
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