On Wed, 12 Aug 2015 07:24:00 AM Chris Murphy 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. Linux Software RAID scrub will copy the data from one disk to the other to make them identical, the theory is that it's best to at least be consistent if you can't be sure you are right. Will a BTRFS scrub do this on a non-CoW file? -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/ -- 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
