증상) OpenStack 인스턴스내 물려있는 디스크를 detach 하고 새로운 디스크로 restore 할경우...새로 restore한 디스크를 마운트할때 발생
리부팅하고 다시 마운트하면....정상
# mount -a
# tail -f /var/log/messages
Mar 31 10:48:48 localhost kernel: EXT4-fs (vdc1): mounted filesystem with ordered data mode. Opts: (null)
Mar 31 10:48:48 localhost systemd: Unit VDB.mount is bound to inactive unit dev-disk-by\x2duuid-477f4196\x2d0d04\x2d42e4\x2d918c\x2dad2ae97bedda.device. Stopping, too.
Mar 31 10:48:48 localhost systemd: Unmounting /VDB...
Mar 31 10:48:48 localhost systemd: Unmounted /VDB.
