ZFS and block deduplication

[markw-FJ05HQ0HCKaWd6l5hS35sQ at public.gmane.org (Mark Woodward)]

On 04/25/2011 09:32 AM, Daniel Feenberg wrote:
>
>
> On Mon, 25 Apr 2011, Mark Woodward wrote:
>
>> This is one of those things that make my brain hurt. If I am
>> representing more data with a fixed size number, i.e. a 4K block vs a
>> 16K block, that does, in fact, increase the probability of collision 4X,
>
> Only for very small blocks. Once the block is larger than the hash, 
> the probability of a collision is independent of the block size.

I think that statement sums up the conceptual gulf between the two 
sides. Its kinda like old school "god does not play dice" physicists and 
the quantum mechanical physicists.