On Mar 23, 2010, at 11:21 PM, Daniel Carosone wrote: > On Tue, Mar 23, 2010 at 07:22:59PM -0400, Frank Middleton wrote: >> On 03/22/10 11:50 PM, Richard Elling wrote: >> >>> Look again, the checksums are different. >> >> Whoops, you are correct, as usual. Just 6 bits out of 256 different... >> >> Look which bits are different - digits 24, 53-56 in both cases. > > This is very likely an error introduced during the calculation of > the hash, rather than an error in the input data. I don't know how > that helps narrow down the source of the problem, though..
The exact same code is used to calculate the checksum when writing or reading. However, we assume the processor works and Frank's tests do not indicate otherwise. > > It suggests an experiment: try switching to another hash algorithm. > It may move the problem around, or even make it worse, of course. > > I'm also reminded of a thread about the implementation of fletcher2 > being flawed, perhaps you're better switching regardless. Clearly, fletcher2 identified the problem. -- richard ZFS storage and performance consulting at http://www.RichardElling.com ZFS training on deduplication, NexentaStor, and NAS performance Las Vegas, April 29-30, 2010 http://nexenta-vegas.eventbrite.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
