Re: Triple-parity raid6

[Joe Landman <joe.landman@gmail.com>]

A quick note of caution (and someone from Netapp, feel free to speak up).

Netapp has a patent on triple parity raid (c.f. 
http://www.freepatentsonline.com/7640484.html).  A quick look over this, 
suggests that the major innovation is the layout and computation which 
they simplified in a particular manner.  That is, I don't think their 
patent covers triple parity RAID in general, but does cover their 
implementation, and the diagonal parity with anti-diagonal parity 
(effectively counter propagating or orthogonalized parity).

I am not sure what this means from a coding sense, other than not to use 
their techniques without a license to do so.  If Netapp wants to grant 
such a license, this would be good, but I suspect that it wouldn't be 
quite as simple as this.

Just a note so that we don't encounter problems.  I think its very 
possible to avoid their IP, as it would somewhat hard to claim ownership 
of the Galois Field math behind RAID calculations.  They can (and do) 
claim a particular implementation and algorithm.

[also not trying to open the patent on code wars here, just pointing out 
the current situation ]


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Joseph Landman, Ph.D
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