On Jan 7, 2011, at 6:13 AM, David Magda wrote: > On Fri, January 7, 2011 01:42, Michael DeMan wrote: >> Then - there is the other side of things. The 'black swan' event. At >> some point, given percentages on a scenario like the example case above, >> one simply has to make the business justification case internally at their >> own company about whether to go SHA-256 only or Fletcher+Verification? >> Add Murphy's Law to the 'black swan event' and of course the only data >> that is lost is that .01% of your data that is the most critical? > > The other thing to note is that by default (with de-dupe disabled), ZFS > uses Fletcher checksums to prevent data corruption. Add also the fact all > other file systems don't have any checksums, and simply rely on the fact > that disks have a bit error rate of (at best) 10^-16. > Agreed - but I think it is still missing the point of what the original poster was asking about.
In all honesty I think the debate is a business decision - the highly improbable vs. certainty. Somebody somewhere must have written this stuff up, along with simple use cases? Perhaps even a new acronym? MTBC - mean time before collision? And even with the 'certainty' factor being the choice - other things like human error come in to play and are far riskier? _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
