btrfs has still many weird issues. e.g. you can't remove a drive if it has I/O errors, even if the rest of the array has still enough space to accompany the dat

btrfs has still many weird issues. e.g. you can't remove a drive if it has I/O errors, even if the rest of the array has still enough space to accompany the data. You can do a replace, but then you need to buy a new drive.