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@(#)umount.8 8.2 (Berkeley) 5/8/95
.Dd July 1, 2025 .Dt UMOUNT 8 .Os .Sh NAME .Nm umount .Nd unmount file systems .Sh SYNOPSIS .Nm .Op Fl dfvFR .Op Fl t Ar fstypelist .Ar special | node .Nm .Fl a .Op Fl dfvF .Op Fl h Ar host .Op Fl t Ar fstypelist .Sh DESCRIPTION The .Nm command calls the .Xr unmount 2 system call (or an external unmount program) 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.
p By default, the file system type is extracted from the kernel and used to choose an external unmount program, whose name is formed by appending an underscore and the type string to .Dq umount . This matches the form used by the external mount programs used by .Xr mount 8 . If this program is found on the path, it is used in preference to calling .Xr unmount 2 directly. Note that in the .Nx base system no such external unmount programs exist; the facility is provided in the hopes that it will be useful for third party file systems and/or for research.
p The options are as follows: l -tag -width indent t Fl a All the currently mounted file systems except the root are unmounted. t Fl d If the filesystem is mounted on a .Xr vnd 4 device (a vnode disk), unconfigure it after .Xr unmount 2 . t 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. t Fl F Fake the unmount; perform all other processing but do not actually attempt the unmount. (This is most useful in conjunction with .Fl v , to see what .Nm would attempt to do). t Fl R Take the .Ar special | node argument as a path to be passed directly to .Xr unmount 2 , bypassing all attempts to be smart about mechanically determining the correct path from the argument. This option is incompatible with any option that potentially unmounts more than one file system, such as .Fl a , but it can be used with .Fl f and/or .Fl v . This is the only way to unmount something that does not appear as a directory (such as a nullfs mount of a plain file); there are probably other cases where it is necessary. This option also disables the use of any external unmount program. t 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 NFS file systems. t Fl t Ar fstypelist 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: d -literal -offset indent umount -a -t nfs,mfs .Ed
p unmounts all file systems of the type .Tn NFS and .Tn MFS , whereas the .Nm command: d -literal -offset indent umount -a -t nonfs,mfs .Ed
p unmounts all file systems except those of type .Tn NFS and .Tn MFS . t Fl v Verbose, additional information is printed out as each file system is unmounted. Giving this option more than once adds additional information. .El .Sh FILES l -tag -width /etc/fstab -compact t Pa /etc/fstab file system table .El .Sh SEE ALSO .Xr unmount 2 , .Xr fstab 5 , .Xr mount 8 , .Xr vndconfig 8 .Sh HISTORY A .Nm command appeared in .At v1 . .Sh BUGS The .Fl d option cannot unconfigure .Xr vnd 4 devices that are mounted via an intermediary layer (e.g., a .Xr dk 4 wedge).
Indexes created Sat Sep 27 22:09:54 GMT 2025