Unknown option: "-8" Unix manual page for umount. (host=minya system=Darwin)
UMOUNT(8)                 BSD 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 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 other-
             wise specified with the -t option, will only unmount NFS filesys-
             tems.

     -t type
             Is used to indicate the actions should only be taken on filesys-
             tems 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.

4th Berkeley Distribution         May 8, 1995        4th Berkeley Distribution