ReclaiMe Data Recovery Training

RAID Recovery Course - Content Analysis Test

Look at the picture on the right and guess RAID level

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

Rows in a parity-based RAID are always even

true
false

What is the first step in RAID recovery?

parity analysis
content analysis
entropy analysis

60-80% ratio of data similarity points to

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

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

If you see several mirror pairs in mirror map, it points to

RAID1
RAID5
Ex-hotspare disk
RAID10

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

RAID1
Ex-hotspare disk
RAID10
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 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 in parity analysis you see 0% parity for full disk set and 100% parity with one disk excluded, what the array level is?

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

Next lesson - Parity Analysis

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