Hi list, Le 31/12/2019 à 23:58, Zygo Blaxell a écrit : > A full balance includes a metadata balance. The primary effect > of metadata balance is to temporarily reduce space for metadata. > Reducing metadata space causes an assortment of problems for btrfs, > only one of which is hitting the 5.4 free space bug. For all but a few > contrived test cases, btrfs manages metadata well without interference > from balance. Too much metadata balancing (i.e. any at all) can make > a filesystem truly run out of metadata space on disk--a condition that > is sometimes difficult to reverse. I however was hit by the "dummy zero free space condition" using 5.4 on a machine, and the resulting filesystem (on an external HD) then still showed 0% free using a 5.3 or a 4.15 kernel on other machines. It however passsed "btrfs check" without any error. The thing that fixed it and returned it to a « normal working state » has been running a "btrfs balance -m" (on the 5.4 machine) on it. So I'm a bit puzzled reading that metadata balance is useless when it precisely fixed this issue on a FS here. Kind regards (and best wishes for a happy new year).
