Re: On the subject of RAID-6 corruption recovery

Thiemo Nagel wrote:

Inverting your argumentation, that means when we don't see z >= n or
inconsistent z numbers, multidisc corruption can be excluded statistically.

For errors occurring on the level of hard disk blocks (signature: most
bytes of the block have D errors, all with same z), the probability for
multidisc corruption to go undetected is ((n-1)/256)**512.  This might
pose a problem in the limiting case of n=255, however for practical
applications, this probability is negligible as it drops off
exponentially with decreasing n:

That assumes fully random data distribution, which is almost certainly a false assumption.

	-hpa