On Wed, Apr 17, 2013 at 11:21 AM, Jim Klimov <[email protected]> wrote:
> On 2013-04-17 20:09, Jay Heyl wrote: > >> reply. Unless the first device to answer returns garbage (something >>> that doesn't match the expected checksum), other copies are not read >>> as part of this request. >>> >>> >> Ah, that makes much more sense. Thanks for the clarification. Now that you >> put it that way I have to wonder how I ever came under the impression it >> was any other way. >> > > > Well, there are different architectures, so some might do what you > suggested. From what I read just yesterday, RAM mirroring on some > high-end servers works indeed like you described - by reading both > parts and comparing the results, testing ECC if needed, etc. to > figure out the correct memory contents or return an error if both > parts are faulty and can't be trusted (ECC mismatch on both). > > Military, nuclear and space systems often are built like 3 or 5 > computers (odd amount for easier quorum) doing the same calculations > over same inputs, and comparing the results to be sure of them or to > redo the task. > > So I guess it depends on your background - why you thought this of > disk systems ;) Actually, I'm pretty sure I read it somewhere on the internet. My fault for thinking every guy with a blog actually knows what he's talking about. :-) _______________________________________________ OpenIndiana-discuss mailing list [email protected] http://openindiana.org/mailman/listinfo/openindiana-discuss
