The command for unmounting a filesystem requires only the
name of the special device or the mount point.
After you have copied in
a filesystem from a diskette, for example,
you can enter the following command
to free the diskette drive:
When unmounting a filesystem being used
by other processes
(including your own shell process, if your current directory is on the filesystem
you want to unmount),
fails and displays the following message:
umount: file_system busy.
To kill the processes using the filesystem, enter:
Unmounting is frequently
a first step before using other commands
that operate on filesystems.
which checks and repairs a filesystem,
works on unmounted filesystems.
Unmounting is also an important part of the process of
shutting down the system.