xref: /freebsd/sbin/umount/umount.8 (revision f0a75d274af375d15b97b830966b99a02b7db911)
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28.\"     @(#)umount.8	8.2 (Berkeley) 5/8/95
29.\" $FreeBSD$
30.\"
31.Dd July 18, 2003
32.Dt UMOUNT 8
33.Os
34.Sh NAME
35.Nm umount
36.Nd unmount file systems
37.Sh SYNOPSIS
38.Nm
39.Op Fl fv
40.Ar special | node | fsid
41.Nm
42.Fl a | A
43.Op Fl F Ar fstab
44.Op Fl fv
45.Op Fl h Ar host
46.Op Fl t Ar type
47.Sh DESCRIPTION
48The
49.Nm
50utility calls the
51.Xr unmount 2
52system call to remove a file system from the file system tree.
53The file system can be specified by its
54.Ar special
55device or remote node (rhost:path), the path to the mount point
56.Ar node
57or by the file system ID
58.Ar fsid
59as reported by
60.Dq mount -v .
61.Pp
62The options are as follows:
63.Bl -tag -width indent
64.It Fl a
65All the file systems described in
66.Xr fstab 5
67are unmounted.
68.It Fl A
69All the currently mounted file systems except
70the root are unmounted.
71.It Fl F Ar fstab
72Specify the
73.Pa fstab
74file to use.
75.It Fl f
76The file system is forcibly unmounted.
77Active special devices continue to work,
78but all other files return errors if further accesses are attempted.
79The root file system cannot be forcibly unmounted.
80.It Fl h Ar host
81Only file systems mounted from the specified host will be
82unmounted.
83This option implies the
84.Fl A
85option and, unless otherwise specified with the
86.Fl t
87option, will only unmount
88.Tn NFS
89file systems.
90.It Fl t Ar type
91Is used to indicate the actions should only be taken on
92file systems of the specified type.
93More than one type may be specified in a comma separated list.
94The list of file system types can be prefixed with
95.Dq no
96to specify the file system types for which action should
97.Em not
98be taken.
99For example, the
100.Nm
101command:
102.Bd -literal -offset indent
103umount -a -t nfs,nullfs
104.Ed
105.Pp
106unmounts all file systems of the type
107.Tn NFS
108and
109.Tn NULLFS
110that are listed in the
111.Xr fstab 5
112file.
113.It Fl v
114Verbose, additional information is printed out as each file system
115is unmounted.
116.El
117.Sh ENVIRONMENT
118.Bl -tag -width ".Ev PATH_FSTAB"
119.It Ev PATH_FSTAB
120If the environment variable
121.Ev PATH_FSTAB
122is set, all operations are performed against the specified file.
123.Ev PATH_FSTAB
124will not be honored if the process environment or memory address space is
125considered
126.Dq tainted .
127(See
128.Xr issetugid 2
129for more information.)
130.El
131.Sh FILES
132.Bl -tag -width /etc/fstab -compact
133.It Pa /etc/fstab
134file system table
135.El
136.Sh SEE ALSO
137.Xr unmount 2 ,
138.Xr fstab 5 ,
139.Xr mount 8
140.Sh HISTORY
141A
142.Nm
143utility appeared in
144.At v6 .
145