diff --git a/src/borg/archiver.py b/src/borg/archiver.py index 8fe1b1da0..1481d5188 100644 --- a/src/borg/archiver.py +++ b/src/borg/archiver.py @@ -3448,13 +3448,13 @@ class Archiver: The ``-x`` or ``--one-file-system`` option excludes directories, that are mountpoints (and everything in them). It detects mountpoints by comparing the device number from the output of ``stat()`` of the directory and its parent directory. Specifically, it excludes directories for which ``stat()`` reports a device number different - from the device number of their parent. Be aware that in Linux (and possibly elsewhere) there are directories - with device number different from their parent, which the kernel does not consider a mountpoint and also the - other way around. Examples are bind mounts (possibly same device number, but always a mountpoint) and ALL - subvolumes of a btrfs (different device number from parent but not necessarily a mountpoint). Therefore when - using ``--one-file-system``, one should make doubly sure that the backup works as intended especially when using - btrfs. This is even more important, if the btrfs layout was created by someone else, e.g. a distribution - installer. + from the device number of their parent. + In general: be aware that there are directories with device number different from their parent, which the kernel + does not consider a mountpoint and also the other way around. + Linux examples for this are bind mounts (possibly same device number, but always a mountpoint) and ALL + subvolumes of a btrfs (different device number from parent but not necessarily a mountpoint). + macOS examples are the apfs mounts of a typical macOS installation. + Therefore, when using ``--one-file-system``, you should double-check that the backup works as intended. .. _list_item_flags: