osx man page for umount

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 otherwise speci-
	     fied 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 filesystems of the type NFS and HFS.

     -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