On Thu, Jun 28, 2018 at 6:27 PM, Chris Murphy <li...@colorremedies.com> wrote: > And an open question I have about scrub is weather it only ever is > checking csums, meaning nodatacow files are never scrubbed, or if the > copies are at least compared to each other?
Scrub never looks at nodatacow files. It does not compare the copies to each other. Qu submitted a patch to make check compare the copies: https://patchwork.kernel.org/patch/10434509/ This hasn't been added to btrfs-progs git yet. IMO, I think the offline check should look at nodatacow copies like this, but I still think this also needs to be added to scrub. In the patch thread, I discuss my reasons why. In brief: online scanning; this goes along with user's expectation of scrub ensuring mirrored data integrity; and recommendations to setup scrub on periodic basis to me means it's the place to put it. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html