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.\" @(#)umount.8 8.2 (Berkeley) 5/8/95
.\" $FreeBSD$
.\"
.Dd April 7, 2003
.Dt UMOUNT 8
.Os
.Sh NAME
.Nm umount
.Nd unmount file systems
.Sh SYNOPSIS
.Nm
.Op Fl fv
.Ar special \&| node
.Nm
.Fl a | A
.Op Fl F Ar fstab
.Op Fl fv
.Op Fl h Ar host
.Op Fl t Ar type
.Sh DESCRIPTION
The
.Nm
utility calls the
.Xr unmount 2
system call to remove a
.Ar "special device"
or the remote node (rhost:path) from the file system tree at the point
.Ar node .
If either
.Ar special
or
.Ar node
are not provided, the appropriate information is taken from the
.Xr fstab 5
file.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl a
All the file systems described in
.Xr fstab 5
are unmounted.
.It Fl A
All the currently mounted file systems except
the root are unmounted.
.It Fl F Ar fstab
Specify the
.Pa fstab
file to use.
.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 file systems 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
.Tn NFS
file systems.
.It Fl t Ar type
Is used to indicate the actions should only be taken on
file systems of the specified type.
More than one type may be specified in a comma separated list.
The list of file system types can be prefixed with
.Dq no
to specify the file system types for which action should
.Em not
be taken.
For example, the
.Nm
command:
.Bd -literal -offset indent
umount -a -t nfs,nullfs
.Ed
.Pp
unmounts all file systems of the type
.Tn NFS
and
.Tn NULLFS
that are listed in the
.Xr fstab 5
file.
.It Fl v
Verbose, additional information is printed out as each file system
is unmounted.
.El
.Sh ENVIRONMENT
.Bl -tag -width ".Ev PATH_FSTAB"
.It Ev PATH_FSTAB
If the environment variable
.Ev PATH_FSTAB
is set, all operations are performed against the specified file.
.Ev PATH_FSTAB
will not be honored if the process environment or memory address space is
considred
.Dq tainted .
(See
.Xr issetugid 2
for more information.)
.El
.Sh FILES
.Bl -tag -width /etc/fstab -compact
.It Pa /etc/fstab
file system table
.El
.Sh SEE ALSO
.Xr unmount 2 ,
.Xr fstab 5 ,
.Xr mount 8
.Sh HISTORY
A
.Nm
utility appeared in
.At v6 .
