.\"	$OpenBSD: umount.8,v 1.16 2007/05/31 19:19:48 jmc Exp $
.\"	$NetBSD: umount.8,v 1.2 1995/03/18 15:01:35 cgd Exp $
.\"
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.\"     @(#)umount.8	8.1 (Berkeley) 2/20/94
.\"
.Dd $Mdocdate: May 31 2007 $
.Dt UMOUNT 8
.Os
.Sh NAME
.Nm umount
.Nd unmount file systems
.Sh SYNOPSIS
.Nm umount
.Op Fl fv
.Ar special | node
.Nm umount
.Fl a
.Op Fl fv
.Op Fl h Ar host
.Op Fl t Ar type
.Sh DESCRIPTION
The
.Nm
command
calls the
.Xr unmount 2
system call to remove a
.Ar special
device or
.Ar node
.Pf ( Bo Ar rhost :
.Bc Ar path )
from the file system tree.
Multiple devices and nodes may be specified on the command line.
If neither
.Ar special
nor
.Ar node
are provided, the appropriate information is taken from the kernel.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl a
All of the file systems except root returned by
.Xr getmntinfo 3
are unmounted.
.It Fl 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.
.It Fl h Ar host
Only filesystems mounted from the specified host will be
unmounted.
This option implies the
.Fl a
option and, unless otherwise specified with the
.Fl t
option, will only unmount NFS filesystems.
.It Fl t Ar 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
.Dq no
to specify the filesystem types for which action should
.Em not
be taken.
For example, the following command
unmounts all filesystems of type
NFS and MFS:
.Bd -literal -offset indent
# umount -a -t nfs,mfs
.Ed
.It Fl v
Verbose, additional information is printed out as each file system
is unmounted.
.El
.Sh SEE ALSO
.Xr unmount 2 ,
.Xr getmntinfo 3 ,
.Xr mount 8
.Sh HISTORY
A
.Nm
command appeared in
.At v3 .