xref: /freebsd/sbin/umount/umount.8 (revision 7773002178c8dbc52b44e4d705f07706409af8e4)
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32.\"     @(#)umount.8	8.2 (Berkeley) 5/8/95
33.\" $FreeBSD$
34.\"
35.Dd July 18, 2003
36.Dt UMOUNT 8
37.Os
38.Sh NAME
39.Nm umount
40.Nd unmount file systems
41.Sh SYNOPSIS
42.Nm
43.Op Fl fv
44.Ar special | node | fsid
45.Nm
46.Fl a | A
47.Op Fl F Ar fstab
48.Op Fl fv
49.Op Fl h Ar host
50.Op Fl t Ar type
51.Sh DESCRIPTION
52The
53.Nm
54utility calls the
55.Xr unmount 2
56system call to remove a file system from the file system tree.
57The file system can be specified by its
58.Ar special
59device or remote node (rhost:path), the path to the mount point
60.Ar node
61or by the file system ID
62.Ar fsid
63as reported by
64.Dq mount -v .
65.Pp
66The options are as follows:
67.Bl -tag -width indent
68.It Fl a
69All the file systems described in
70.Xr fstab 5
71are unmounted.
72.It Fl A
73All the currently mounted file systems except
74the root are unmounted.
75.It Fl F Ar fstab
76Specify the
77.Pa fstab
78file to use.
79.It Fl f
80The file system is forcibly unmounted.
81Active special devices continue to work,
82but all other files return errors if further accesses are attempted.
83The root file system cannot be forcibly unmounted.
84.It Fl h Ar host
85Only file systems mounted from the specified host will be
86unmounted.
87This option implies the
88.Fl A
89option and, unless otherwise specified with the
90.Fl t
91option, will only unmount
92.Tn NFS
93file systems.
94.It Fl t Ar type
95Is used to indicate the actions should only be taken on
96file systems of the specified type.
97More than one type may be specified in a comma separated list.
98The list of file system types can be prefixed with
99.Dq no
100to specify the file system types for which action should
101.Em not
102be taken.
103For example, the
104.Nm
105command:
106.Bd -literal -offset indent
107umount -a -t nfs,nullfs
108.Ed
109.Pp
110unmounts all file systems of the type
111.Tn NFS
112and
113.Tn NULLFS
114that are listed in the
115.Xr fstab 5
116file.
117.It Fl v
118Verbose, additional information is printed out as each file system
119is unmounted.
120.El
121.Sh ENVIRONMENT
122.Bl -tag -width ".Ev PATH_FSTAB"
123.It Ev PATH_FSTAB
124If the environment variable
125.Ev PATH_FSTAB
126is set, all operations are performed against the specified file.
127.Ev PATH_FSTAB
128will not be honored if the process environment or memory address space is
129considred
130.Dq tainted .
131(See
132.Xr issetugid 2
133for more information.)
134.El
135.Sh FILES
136.Bl -tag -width /etc/fstab -compact
137.It Pa /etc/fstab
138file system table
139.El
140.Sh SEE ALSO
141.Xr unmount 2 ,
142.Xr fstab 5 ,
143.Xr mount 8
144.Sh HISTORY
145A
146.Nm
147utility appeared in
148.At v6 .
149