ReclaiMe Data Recovery Training

RAID Recovery Course - Content Analysis Test

If you see one partial mirror pair (60-80%) in mirror map, it points to

RAID10
Ex-hotspare disk
RAID1
RAID5

Check for what parity tests are done

full disk set
each member disk
all disk pairs
all combinations with one disk excluded

Parity test for a full regular RAID5 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

What does parity analysis calculate?

percent of parity matches in each disk pair
percent of parity matches in each disk
percent of parity matches in disk set

Check the possible RAID levels if parity analysis gives you 0% parity both for full disk set and exclusion combinations

If you see one mirror pair in mirror map, it points to

Ex-hotspare disk
RAID10
RAID1
RAID5

Look at the picture and choose the possible variant

Disks {4,5,7} belong to one RAID; Disk 6 is a hotspare
Disks {4,5,6} belong to one RAID; Disk 7 is a hotspare
Disks {5,6,7} belong to one RAID; Disk 4 is a hotspare

Look at the picture on the right and guess RAID level

full 4-disk RAID 5
4-disk RAID 5 with one disk missing
3-disk RAID 5 with a hotspare
RAID0

60-80% ratio of data similarity points to

different disks
mirror pair
ex-hotspare disk or out-of-sync mirror

95-100% ratio of data similarity points to

ex-hotspare disk
different disks
mirror pair

Next lesson - Parity Analysis

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