Exotic RAID types

By Geek -
With a RAID recovery, certain exotic RAID types can be recovered using the same basic algorithms, because these exotic RAID types can be reduced to one of the three basic types (RAID0, RAID1, and RAID5).
The list goes like this:
  • RAID 1+0 or 0+1 can either be reduced to RAID 0 by removing mirrors (near layout), or can be recovered as a RAID 0 straight away (far layout).
  • RAID 5E or RAID 6E can be recovered as a RAID 5 or RAID 6 respectively, because all the extra data is at the end of the array.
  • RAID 5EE can be recovered as RAID 6 with one of the sets of parity corrupt.
  • RAID 4 is actually a variation of RAID 5 where parity does not change position across rows.
The array types requiring special processing are RAID 1+0 using offset layout and RAID 1E.

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