On Tue, Aug 11, 2015 at 5:24 PM, Chris Murphy <lists@xxxxxxxxxxxxxxxxx> wrote: >> There is still data redundancy. Will a scrub at least notice that the >> copies differ? > > No, that's what I mean by "nodatasum means no raid1 self-healing is > possible". You have data redundancy, but without checksums btrfs has > no way to know if they differ. It doesn't do two reads and compares > them, it's just like md raid, it picks one device, and so long as > there's no read error from the device, that copy of the data is > assumed to be good. Ok, that makes sense. I'm guessing it wouldn't be worth it to add a feature like this because (a) few people use nodatacow or end up in my situation, and (b) if they did, and the two copies were inconsistent, what would you do? I suppose for me, it would be nice to know which files were affected. -- Timothy Normand Miller, PhD Assistant Professor of Computer Science, Binghamton University http://www.cs.binghamton.edu/~millerti/ Open Graphics Project -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
