UMOUNT(8)           Linux Programmer's Manual           UMOUNT(8)

NAME
       umount - unmount file systems

SYNOPSIS
       umount [-hV]

       umount -a [-nrv] [-t vfstype]
       umount [-nrv] device | dir [...]

DESCRIPTION
       The  umount  command detaches the file system(s) mentioned
       from the file  hierarchy.   A  file  system  is  specified
       either  by giving the directory where it has been mounted,
       or by giving the special device on which it lives.

       Note that a file system cannot be  unmounted  when  it  is
       `busy'  - for example, when there are open files on it, or
       when some process has its working directory there, or when
       a  swap file on it is in use.  The offending process could
       even be umount itself - it opens libc,  and  libc  in  its
       turn may open for example locale files.

       Options for the umount command:

       -V     Print version and exit.

       -h     Print help message and exit.

       -v     Verbose mode.

       -n     Unmount without writing in /etc/mtab.

       -r     In case unmounting fails, try to remount read-only.

       -a     All of the file systems described in /etc/mtab  are
              unmounted.  (With umount version 2.7 and later: the
              proc filesystem is not unmounted.)

       -t vfstype
              Indicate that the actions should only be  taken  on
              file  systems of the specified type.  More than one
              type may be specified in a  comma  separated  list.
              The  list of file system types can be prefixed with
              no to specify the file system  types  on  which  no
              action should be taken.

THE LOOP DEVICE
       The  umount  command  will  free  the loop device (if any)
       associated with the mount, in case  it  finds  the  option
       `loop=...'  in /etc/mtab.  Any pending loop devices can be
       freed using `losetup -d', see losetup(8).

FILES
       /etc/mtab table of mounted file systems

SEE ALSO
       umount(2), mount(8), losetup(8).

HISTORY
       A umount command appeared in Version 6 AT&T UNIX.

Linux 2.0                  26 July 1997                         1