07.06.2020 13:09, Goffredo Baroncelli пишет: >> >> Unallocated: >> /dev/mapper/btrfs1 1.02MiB >> /dev/mapper/btrfs2 930.49GiB > > The old disk is full. And the fact that Metadata has a raid1 profile > prevent further metadata allocation/reshape. > The filesystem goes RO after the mount ? If no a simple balance of > metadata should be enough; pay attention to select > "single" profile for metadata for this first attempt. > > # btrfs balance start -mconvert=single <mnt-point> > > This should free about 4G from the old disk. Then, balance the data > E-h-h ... how btrfs knows it should free 4G from the old and not form the new disk? I guess it is old request to allow explicitly select "victim" and "target" devices during balance. IOW can we rely on btrfs doing "the right thing" always or is just coincidence?
