UMOUNT(8)                   System Manager's Manual                  UMOUNT(8)

NAME
     umount – unmount filesystems

SYNOPSIS
     umount [-fv] special | node
     umount -a | -A [-fv] [-h host] [-t type]

DESCRIPTION
     The umount command unmounts a mounted filesystem (volume), removing it
     from the filesystem namespace.  It calls the unmount(2) system call to
     remove a special device or the remote node (rhost:path) from the
     filesystem tree at the point node.  If either special or node are not
     provided, the appropriate information is taken from the list of
     filesystems provided by getfsent(3).

     The options are as follows:

     -a      All the filesystems described via getfsent(3) are unmounted.

     -A      All the currently mounted filesystems except the root are
             unmounted.

     -f      The filesystem is forcibly unmounted.  Active special devices
             continue to work, but all other files return errors if further
             accesses are attempted.  The root filesystem cannot be forcibly
             unmounted.

     -h host
             Only filesystems mounted from the specified host will be
             unmounted.  This option implies the -A option and, unless
             otherwise specified with the -t option, will only unmount NFS
             filesystems.

     -t type
             Is used to indicate the actions should only be taken on
             filesystems of the specified type.  More than one type may be
             specified in a comma separated list.  The list of filesystem
             types can be prefixed with “no” to specify the filesystem types
             for which action should not be taken.  For example, the umount
             command:

                   umount -A -t nfs,hfs

             umounts all currently-mounted filesystems of the type NFS and
             HFS.  (The -a option only unmounts entries in the /etc/fstab
             list.)

     -v      Verbose, additional information is printed out as each filesystem
             is unmounted.

NOTES
     Due to the complex and interwoven nature of Mac OS X, umount may fail
     often.  It is recommended that diskutil(1) (as in, ``diskutil unmount
     /mnt'') be used instead.

SEE ALSO
     unmount(2), getfsent(3), mount(8), diskutil(1)

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

BSD 4                             May 8, 1995                            BSD 4