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

NAME
     umount - unmount file systems

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

DESCRIPTION
     The umount command calls the unmount(2) system call to remove a special
     device or node ([rhost:]path) from the file system tree.  Multiple de-
     vices and nodes may be specified on the command line.  If neither special
     nor node are provided, the appropriate information is taken from the ker-
     nel.

     The options are as follows:

     -a      All of the file systems except root returned by getmntinfo(3) are
             unmounted.

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

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

     -t type
             Indicates that 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 following command unmounts
             all filesystems of type NFS and MFS:

                   # umount -a -t nfs,mfs

     -v      Verbose, additional information is printed out as each file sys-
             tem is unmounted.

SEE ALSO
     unmount(2), getmntinfo(3), mount(8)

HISTORY
     A umount command appeared in Version 3 AT&T UNIX.

OpenBSD 4.7                      May 31, 2007                                1
