Sometimes when I want to umount a device, e.g.
sudo umount /dev/loop0
I will get the message
umount: /mnt: device is busy. (In some cases useful info about processes that use the device is found by lsof(8) or fuser(1))
I usually solve this issue by closing a console window (in my case xfce4-terminal) and then
What does this problem mean? Is there some smarter solution?