On Tue, Mar 23, 2021 at 12:50 AM Dave T <davestechs...@gmail.com> wrote: > > > d. Just skip the testing and try usebackuproot with a read-write > > mount. It might make things worse, but at least it's fast to test. If > > it messes things up, you'll have to recreate this backup from scratch. > > I took this approach. My command was simply: > > mount -o usebackuproot /dev/mapper/xzy /backup > > It appears to have succeeded because it mounted without errors. I > completed a new incremental backup (with btrbk) and it finished > without errors. > I'll be pleased if my backup history is preserved, as appears to be the case. > > I will run some checks on those backup subvolumes tomorrow. Are there > specific checks you would recommend?
It will have replaced all the root nodes and super blocks within a minute, or immediately upon umount. So you can just do a 'btrfs check' and see if that comes up clean now. It's basically a kind of rollback and if it worked, there will be no inconsistencies found by btrfs check. -- Chris Murphy
