Carsten Aulbert <carsten.aulbert <at> aei.mpg.de> writes: > > In RAID6 you have redundant parity, thus the controller can find out > if the parity was correct or not. At least I think that to be true > for Areca controllers :)
Are you sure about that ? The latest research I know of [1] says that although an algorithm does exist to theoretically recover from single-disk corruption in the case of RAID-6, it is *not* possible to detect dual-disk corruption with 100% certainty. And blindly running the said algorithm in such a case would even introduce corruption on a third disk. This is the reason why, AFAIK, no RAID-6 implementation actually attempts to recover from single-disk corruption (someone correct me if I am wrong). The exception is ZFS of course, but it accomplishes single and dual-disk corruption self-healing by using its own checksum, which is one layer above RAID-6 (therefore unrelated to it). [1] http://kernel.org/pub/linux/kernel/people/hpa/raid6.pdf -marc _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
