ReclaiMe Data Recovery Training

RAID Recovery Course - Content Analysis Test

You should do mirror analysis before parity analysis because

mirrors are always even and therefore parity analysis does not apply to mirrors
parity analysis destroys mirror data
mirror analysis helps calculate parity more accurately

Check for what parity tests are done

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

Parity test for a full regular RAID5 gives

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

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

RAID10
RAID5
RAID1
Ex-hotspare disk

What does content analysis help determine?

disk order
RAID level
block size

Look at the picture on the right and guess RAID level

RAID5
RAID0
RAID1
RAID10

Look at the picture and choose the possible variant

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

If in parity analysis you see 0% parity for full disk set and 100% parity with one disk excluded, what the array level is?

full regular RAID5
RAID5 with a hotspare disk
certain type of RAID6
RAID5 with a missing disk

Look at the picture on the right and check the possible RAID level(s)

RAID10
RAID 5 with a missing disk
full RAID5
RAID0

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

RAID10
full RAID5
RAID 5 with a missing disk
full RAID 5 with a hotspare

Next lesson - Parity Analysis

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