On 07/11/2012 12:24 PM, Justin Stringfellow wrote: >> Suppose you find a weakness in a specific hash algorithm; you use this >> to create hash collisions and now imagined you store the hash collisions >> in a zfs dataset with dedup enabled using the same hash algorithm..... > > Sorry, but isn't this what dedup=verify solves? I don't see the problem here. > Maybe all that's needed is a comment in the manpage saying hash algorithms > aren't perfect.
It does solve it, but at a cost to normal operation. Every write gets turned into a read. Assuming a big enough and reasonably busy dataset, this leads to tremendous write amplification. Cheers, -- Saso _______________________________________________ zfs-discuss mailing list firstname.lastname@example.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss