umount

[Gert Cuykens]

7rxI# df -h
Filesystem     Size    Used   Avail Capacity  Mounted on
/dev/ar0s2a    248M    114M    114M    50%    /
devfs          1.0K    1.0K      0B   100%    /dev
/dev/ar0s2e    248M    5.1M    223M     2%    /tmp
/dev/ar0s2f     35G    2.6G     29G     8%    /usr
/dev/ar0s2d    248M     22M    206M    10%    /var
/dev/ar0s1     100G     17G     83G    17%    /mnt
7rxI# umount /dev/ar0s1
umount: unmount of /mnt failed: Device busy
7rxI#

Why does it not want to unmount /dev/ar0s1 ?