Listing a root directory or fetching attributes about "/buse" directory returns error:
~# ls -ld /buse ls: cannot access buse: Transport endpoint is not connected d????????? ? ? ? ? ? buse ~#
This directory is in use for "backups in user-space" daemon, which allows attaching backups to the respective virtual environments (containers). The error means that the corresponding process is no longer running, however the FUSE-based file-system was not unmounted properly.
Remount the file-system:
~# fusermount -u /buse ~# mount /buse